TY  - JOUR
AU  - Tadić, Marin
AU  - Lazović, Jelena
AU  - Panjan, Matjaž
AU  - Kralj, Slavko
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10189
AB  - Controlled spatial arrangements of superparamagnetic iron oxide nanoparticles (SPIONs) in complex nanostructures determine fine tuning of physico-chemical properties which, in turn, may lead to new practical applications. We report here on newly observed properties of hierarchical SPIONs nanostructure with bundle-like morphology, also known as nanobundles. Colloidal chemical processes and sol-gel synthesis were used for the synthesis of nanobundles, i.e. i) self-assembly of SPIONs into magnetic nanoparticle clusters, ii) their magnetic assembly to the nanochains, and finally iii) formation of bundle-like hierarchical nanostructure. An XRPD measurements show spinel crystal structure of maghemite/magnetite nanoparticles, EDS analysis reveals Fe, Si and O as main elements whereas SEM/TEM analysis show silica-coated magnetic nanoclusters (∼100 nm) and their hierarchical assemblies with bundle-like morphology of ∼8 μm length and ∼1 μm width. TEM analysis revealed core-shell nature of iron oxide nanoparticle clusters with their size of around 80 nm that were coated by an amorphous silica shell with thickness of ∼15 nm. The nanoclusters in the core are constructed of maghemite/magnetite nanoparticle assembly with primary iron oxide nanoparticle size about 10 nm. The magnetization M data as a function of an applied external magnetic field H were successfully fitted by the Langevin function, whence the magnetic moment μp = 19256 μB, and the diameter d = 9.6 nm of nanoparticles were determined. Microsized bundle-like particles are superparamagnetic, magnetically guidable and possess high transverse relaxivity of r2 = 397.8 mM−1s−1. Magnetic properties and such high value of transverse relaxivity holds promise for nanobundles application in MRI imaging (MRI contrast agent), as nanobundles may enhance the magnetic field in their surroundings and enhance proton relaxation processes. Our nanobundles can open new opportunities in the biomedical applications, magnetic separation, photonic crystals and magnetic liquid manipulation and can be inspiration for synthesizing novel self-assembled nanoparticle structures. © 2022 Elsevier Ltd and Techna Group S.r.l.
T2  - Ceramics International
T1  - Hierarchical iron oxide nanocomposite: Bundle-like morphology, magnetic properties and potential biomedical application
SP  - Early view
DO  - 10.1016/j.ceramint.2022.02.145
ER  - 

@article{
author = "Tadić, Marin and Lazović, Jelena and Panjan, Matjaž and Kralj, Slavko",
year = "2022",
abstract = "Controlled spatial arrangements of superparamagnetic iron oxide nanoparticles (SPIONs) in complex nanostructures determine fine tuning of physico-chemical properties which, in turn, may lead to new practical applications. We report here on newly observed properties of hierarchical SPIONs nanostructure with bundle-like morphology, also known as nanobundles. Colloidal chemical processes and sol-gel synthesis were used for the synthesis of nanobundles, i.e. i) self-assembly of SPIONs into magnetic nanoparticle clusters, ii) their magnetic assembly to the nanochains, and finally iii) formation of bundle-like hierarchical nanostructure. An XRPD measurements show spinel crystal structure of maghemite/magnetite nanoparticles, EDS analysis reveals Fe, Si and O as main elements whereas SEM/TEM analysis show silica-coated magnetic nanoclusters (∼100 nm) and their hierarchical assemblies with bundle-like morphology of ∼8 μm length and ∼1 μm width. TEM analysis revealed core-shell nature of iron oxide nanoparticle clusters with their size of around 80 nm that were coated by an amorphous silica shell with thickness of ∼15 nm. The nanoclusters in the core are constructed of maghemite/magnetite nanoparticle assembly with primary iron oxide nanoparticle size about 10 nm. The magnetization M data as a function of an applied external magnetic field H were successfully fitted by the Langevin function, whence the magnetic moment μp = 19256 μB, and the diameter d = 9.6 nm of nanoparticles were determined. Microsized bundle-like particles are superparamagnetic, magnetically guidable and possess high transverse relaxivity of r2 = 397.8 mM−1s−1. Magnetic properties and such high value of transverse relaxivity holds promise for nanobundles application in MRI imaging (MRI contrast agent), as nanobundles may enhance the magnetic field in their surroundings and enhance proton relaxation processes. Our nanobundles can open new opportunities in the biomedical applications, magnetic separation, photonic crystals and magnetic liquid manipulation and can be inspiration for synthesizing novel self-assembled nanoparticle structures. © 2022 Elsevier Ltd and Techna Group S.r.l.",
journal = "Ceramics International",
title = "Hierarchical iron oxide nanocomposite: Bundle-like morphology, magnetic properties and potential biomedical application",
pages = "Early view",
doi = "10.1016/j.ceramint.2022.02.145"
}

Tadić, M., Lazović, J., Panjan, M.,& Kralj, S.. (2022). Hierarchical iron oxide nanocomposite: Bundle-like morphology, magnetic properties and potential biomedical application. in Ceramics International, Early view.
https://doi.org/10.1016/j.ceramint.2022.02.145

Tadić M, Lazović J, Panjan M, Kralj S. Hierarchical iron oxide nanocomposite: Bundle-like morphology, magnetic properties and potential biomedical application. in Ceramics International. 2022;:Early view.
doi:10.1016/j.ceramint.2022.02.145 .

Tadić, Marin, Lazović, Jelena, Panjan, Matjaž, Kralj, Slavko, "Hierarchical iron oxide nanocomposite: Bundle-like morphology, magnetic properties and potential biomedical application" in Ceramics International (2022):Early view,
https://doi.org/10.1016/j.ceramint.2022.02.145 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Panjan, Matjaž
AU  - Vučetić Tadić, Biljana
AU  - Kralj, Slavko
AU  - Lazović, Jelena
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10102
AB  - A porous hematite/alumina nanocomposite is produced by sol-gel combustion synthesis. The XRPD, Raman and FTIR methods show the presence of α-Fe2O3 phase while SEM, TEM, EDS and BET techniques further reveal the formation of porous ellipsoid-like nanostructure of hematite nanoparticles coated by amorphous alumina. Hematite nanoparticles have a size of ~40 nm whereas the porous hematite/alumina nanocomposite particles are ~100 nm in size with characteristic pores of ~7 nm. The M(H) at 300 K exhibits coercivity HC = 293 Oe and magnetization MS = 2.71 emu/g and at 5 K HC = 1150 Oe and MS = 9.25 emu/g. The M(T) under H = 100 Oe shows a bifurcation between ZFC/FC magnetization curves at all measurement temperatures Tirr>350 K (irreversibility temperature) and blocking temperature at TB ~ 305 K. Unexpectedly, the M(T) measurements under H = 10 kOe reveal the suppressed Morin transition at TM = 225 K. The analysis of the results and data from the literature reveal that the porous surface structure of hematite induces the atypical magnetic properties. A magnetic resonance imaging (MRI) properties show the transverse relaxivity rate (r2) of 0.44 mM−1s−1 at 7 T and 1.06 mM−1s−1 at 15.2 T. The investigated nanocomposite particles could be useful in biomedical applications due to their low cytotoxicity and porous nanostructure.
T2  - Ceramics International
T1  - Magnetic properties of mesoporous hematite/alumina nanocomposite and evaluation for biomedical applications
DO  - 10.1016/j.ceramint.2021.12.209
ER  - 

@article{
author = "Tadić, Marin and Panjan, Matjaž and Vučetić Tadić, Biljana and Kralj, Slavko and Lazović, Jelena",
year = "2021",
abstract = "A porous hematite/alumina nanocomposite is produced by sol-gel combustion synthesis. The XRPD, Raman and FTIR methods show the presence of α-Fe2O3 phase while SEM, TEM, EDS and BET techniques further reveal the formation of porous ellipsoid-like nanostructure of hematite nanoparticles coated by amorphous alumina. Hematite nanoparticles have a size of ~40 nm whereas the porous hematite/alumina nanocomposite particles are ~100 nm in size with characteristic pores of ~7 nm. The M(H) at 300 K exhibits coercivity HC = 293 Oe and magnetization MS = 2.71 emu/g and at 5 K HC = 1150 Oe and MS = 9.25 emu/g. The M(T) under H = 100 Oe shows a bifurcation between ZFC/FC magnetization curves at all measurement temperatures Tirr>350 K (irreversibility temperature) and blocking temperature at TB ~ 305 K. Unexpectedly, the M(T) measurements under H = 10 kOe reveal the suppressed Morin transition at TM = 225 K. The analysis of the results and data from the literature reveal that the porous surface structure of hematite induces the atypical magnetic properties. A magnetic resonance imaging (MRI) properties show the transverse relaxivity rate (r2) of 0.44 mM−1s−1 at 7 T and 1.06 mM−1s−1 at 15.2 T. The investigated nanocomposite particles could be useful in biomedical applications due to their low cytotoxicity and porous nanostructure.",
journal = "Ceramics International",
title = "Magnetic properties of mesoporous hematite/alumina nanocomposite and evaluation for biomedical applications",
doi = "10.1016/j.ceramint.2021.12.209"
}

Tadić, M., Panjan, M., Vučetić Tadić, B., Kralj, S.,& Lazović, J.. (2021). Magnetic properties of mesoporous hematite/alumina nanocomposite and evaluation for biomedical applications. in Ceramics International.
https://doi.org/10.1016/j.ceramint.2021.12.209

Tadić M, Panjan M, Vučetić Tadić B, Kralj S, Lazović J. Magnetic properties of mesoporous hematite/alumina nanocomposite and evaluation for biomedical applications. in Ceramics International. 2021;.
doi:10.1016/j.ceramint.2021.12.209 .

Tadić, Marin, Panjan, Matjaž, Vučetić Tadić, Biljana, Kralj, Slavko, Lazović, Jelena, "Magnetic properties of mesoporous hematite/alumina nanocomposite and evaluation for biomedical applications" in Ceramics International (2021),
https://doi.org/10.1016/j.ceramint.2021.12.209 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Milošević, Irena
AU  - Kralj, Slavko
AU  - Hanžel, Darko
AU  - Barudžija, Tanja
AU  - Motte, Laurence
AU  - Makovec, Darko
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8824
AB  - A metastable ε-polymorph of iron(III) oxide (ε-Fe2O3) is a very attractive material from the technological, engineering, and scientific points of view. In comparison with other iron oxides, it is characterized by unusual magnetic properties and a giant coercivity of ~20 kOe, which is the largest value among metal oxides. The routine method of ε-Fe2O3 formation is based on the thermal annealing of maghemite (γ-Fe2O3) nanoparticles confined in a silica matrix where the ε-Fe2O3 appears as an intermediate phase between the maghemite and an α-polymorph (α-Fe2O3) hematite (γ→ε→α pathway). In this study, it is demonstrated that the ε→α transformation can be reversed when hematite nanoparticles with an anisotropic hollow morphology are annealed above 600 °C. The observed reversal of the phase stability is explained in terms of an increased nanoparticle surface area and surface energy related to the hollow structure. This study demonstrates the applicability of surface-induced phase transformation to stabilize and control ε-Fe2O3 nanostructures with anisotropic shape and high coercivity ~1600 kA/m that is one of the key properties of functional magnetic materials for information processing and storage. The understanding of ε-Fe2O3 formation mechanism can provide a new viewpoint and guidance for designing metastable polymorphs and applicative properties. © 2020 Acta Materialia Inc.
T2  - Acta Materialia
T1  - Surface-induced reversal of a phase transformation for the synthesis of ε-Fe2O3 nanoparticles with high coercivity
VL  - 188
SP  - 16
EP  - 22
DO  - 10.1016/j.actamat.2020.01.058
ER  - 

@article{
author = "Tadić, Marin and Milošević, Irena and Kralj, Slavko and Hanžel, Darko and Barudžija, Tanja and Motte, Laurence and Makovec, Darko",
year = "2020",
abstract = "A metastable ε-polymorph of iron(III) oxide (ε-Fe2O3) is a very attractive material from the technological, engineering, and scientific points of view. In comparison with other iron oxides, it is characterized by unusual magnetic properties and a giant coercivity of ~20 kOe, which is the largest value among metal oxides. The routine method of ε-Fe2O3 formation is based on the thermal annealing of maghemite (γ-Fe2O3) nanoparticles confined in a silica matrix where the ε-Fe2O3 appears as an intermediate phase between the maghemite and an α-polymorph (α-Fe2O3) hematite (γ→ε→α pathway). In this study, it is demonstrated that the ε→α transformation can be reversed when hematite nanoparticles with an anisotropic hollow morphology are annealed above 600 °C. The observed reversal of the phase stability is explained in terms of an increased nanoparticle surface area and surface energy related to the hollow structure. This study demonstrates the applicability of surface-induced phase transformation to stabilize and control ε-Fe2O3 nanostructures with anisotropic shape and high coercivity ~1600 kA/m that is one of the key properties of functional magnetic materials for information processing and storage. The understanding of ε-Fe2O3 formation mechanism can provide a new viewpoint and guidance for designing metastable polymorphs and applicative properties. © 2020 Acta Materialia Inc.",
journal = "Acta Materialia",
title = "Surface-induced reversal of a phase transformation for the synthesis of ε-Fe2O3 nanoparticles with high coercivity",
volume = "188",
pages = "16-22",
doi = "10.1016/j.actamat.2020.01.058"
}

Tadić, M., Milošević, I., Kralj, S., Hanžel, D., Barudžija, T., Motte, L.,& Makovec, D.. (2020). Surface-induced reversal of a phase transformation for the synthesis of ε-Fe2O3 nanoparticles with high coercivity. in Acta Materialia, 188, 16-22.
https://doi.org/10.1016/j.actamat.2020.01.058

Tadić M, Milošević I, Kralj S, Hanžel D, Barudžija T, Motte L, Makovec D. Surface-induced reversal of a phase transformation for the synthesis of ε-Fe2O3 nanoparticles with high coercivity. in Acta Materialia. 2020;188:16-22.
doi:10.1016/j.actamat.2020.01.058 .

Tadić, Marin, Milošević, Irena, Kralj, Slavko, Hanžel, Darko, Barudžija, Tanja, Motte, Laurence, Makovec, Darko, "Surface-induced reversal of a phase transformation for the synthesis of ε-Fe2O3 nanoparticles with high coercivity" in Acta Materialia, 188 (2020):16-22,
https://doi.org/10.1016/j.actamat.2020.01.058 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Kralj, Slavko
AU  - Lalatonne, Yoann
AU  - Motte, Laurence
PY  - 2019
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0169433219301138
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8033
AB  - Investigation and synthesis of anisotropic magnetic nanostructures, such as wires, rods, fibers, tubes and chains, is an important field of research due to the beneficial properties and great potential for practical applications ranging from magnetic data storage to biomedicine. Silica coated iron oxide nanochains of length up to 1 μm and diameter ∼80–100 nm have been synthesized by the simultaneous magnetic assembly of superparamagnetic iron oxide nanoparticle clusters (SNCs) as links (viz. maghemite, γ-Fe2O3) and the fixation of the assembled SNCs with an additional layer of deposited silica. We reveal that is possible to achieve either superparamagnetic or ferromagnetic behavior with the nanochains depending only on their physical orientation. The superparamagnetic behavior is observed for random orientation of nanochains whereas ferromagnetic properties (HC ≈ 100 Oe) come to the fore when the orientation is mainly parallel. These peculiar magnetic properties can be related to: (1) the specific size, which is ∼9 nm, of primary building blocks of the nanochains, i.e. of maghemite nanoparticles; (2) to the anisotropic chain-like shape of the particles; and (3) to inter-particle interactions. Large pore volume and pore size of silica shell as well as good colloidal stability and magnetic responsiveness of such nanochains enable applications in biomedicine. © 2019 Elsevier B.V.
T2  - Applied Surface Science
T1  - Iron oxide nanochains coated with silica: Synthesis, surface effects and magnetic properties
VL  - 476
SP  - 641
EP  - 646
DO  - 10.1016/j.apsusc.2019.01.098
ER  - 

@article{
author = "Tadić, Marin and Kralj, Slavko and Lalatonne, Yoann and Motte, Laurence",
year = "2019",
abstract = "Investigation and synthesis of anisotropic magnetic nanostructures, such as wires, rods, fibers, tubes and chains, is an important field of research due to the beneficial properties and great potential for practical applications ranging from magnetic data storage to biomedicine. Silica coated iron oxide nanochains of length up to 1 μm and diameter ∼80–100 nm have been synthesized by the simultaneous magnetic assembly of superparamagnetic iron oxide nanoparticle clusters (SNCs) as links (viz. maghemite, γ-Fe2O3) and the fixation of the assembled SNCs with an additional layer of deposited silica. We reveal that is possible to achieve either superparamagnetic or ferromagnetic behavior with the nanochains depending only on their physical orientation. The superparamagnetic behavior is observed for random orientation of nanochains whereas ferromagnetic properties (HC ≈ 100 Oe) come to the fore when the orientation is mainly parallel. These peculiar magnetic properties can be related to: (1) the specific size, which is ∼9 nm, of primary building blocks of the nanochains, i.e. of maghemite nanoparticles; (2) to the anisotropic chain-like shape of the particles; and (3) to inter-particle interactions. Large pore volume and pore size of silica shell as well as good colloidal stability and magnetic responsiveness of such nanochains enable applications in biomedicine. © 2019 Elsevier B.V.",
journal = "Applied Surface Science",
title = "Iron oxide nanochains coated with silica: Synthesis, surface effects and magnetic properties",
volume = "476",
pages = "641-646",
doi = "10.1016/j.apsusc.2019.01.098"
}

Tadić, M., Kralj, S., Lalatonne, Y.,& Motte, L.. (2019). Iron oxide nanochains coated with silica: Synthesis, surface effects and magnetic properties. in Applied Surface Science, 476, 641-646.
https://doi.org/10.1016/j.apsusc.2019.01.098

Tadić M, Kralj S, Lalatonne Y, Motte L. Iron oxide nanochains coated with silica: Synthesis, surface effects and magnetic properties. in Applied Surface Science. 2019;476:641-646.
doi:10.1016/j.apsusc.2019.01.098 .

Tadić, Marin, Kralj, Slavko, Lalatonne, Yoann, Motte, Laurence, "Iron oxide nanochains coated with silica: Synthesis, surface effects and magnetic properties" in Applied Surface Science, 476 (2019):641-646,
https://doi.org/10.1016/j.apsusc.2019.01.098 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Kralj, Slavko
AU  - Kopanja, Lazar
PY  - 2019
UR  - https://linkinghub.elsevier.com/retrieve/pii/S1044580318323763
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8005
AB  - We report monodisperse, chain-like particles (nanochains) consisted of silica-coated maghemite (γ-Fe2O3) nanoparticle clusters prepared by colloidal chemistry and magnetic field-induced self-assembly of nanoparticle clusters. In order to quantify the shapes of chain-like particles, we have used the measure for shape convexity which is also called solidity. We functionalize the surface of the nanochains with amino (–NH2) and carboxyl groups (–COOH) in order to modify surface charge. These surfaces of nanochains provide better colloidal stability and their potential for practical applications in biomedicine. The enhanced colloidal stability of the surface modified nanochains is confirmed by Zeta potential (ζ-potential) analysis. Magnetic properties of the nanochains show superparamagnetic state at room temperature since the nanochains are composed of tiny nanoparticles as their building blocks. The measured M(H) data at room temperature have been successfully fitted by the Langevin function and magnetic moment μp = 20,526 μB for sphere-like nanoparticle clusters and μp = 20,767 μB for nanochains are determined. The determined magnetic parameters have revealed that the nanochains show a magnetic moment of the nanoparticles higher than the one of individual nanoparticle clusters. These differences can be attributed to the collective magnetic properties of superparamagnetic iron oxide nanoparticles (SPION) assembled in different morphologies (isotropic and anisotropic morphology). © 2018
T2  - Materials Characterization
T1  - Synthesis, particle shape characterization, magnetic properties and surface modification of superparamagnetic iron oxide nanochains
VL  - 148
SP  - 123
EP  - 133
DO  - 10.1016/j.matchar.2018.12.014
ER  - 

@article{
author = "Tadić, Marin and Kralj, Slavko and Kopanja, Lazar",
year = "2019",
abstract = "We report monodisperse, chain-like particles (nanochains) consisted of silica-coated maghemite (γ-Fe2O3) nanoparticle clusters prepared by colloidal chemistry and magnetic field-induced self-assembly of nanoparticle clusters. In order to quantify the shapes of chain-like particles, we have used the measure for shape convexity which is also called solidity. We functionalize the surface of the nanochains with amino (–NH2) and carboxyl groups (–COOH) in order to modify surface charge. These surfaces of nanochains provide better colloidal stability and their potential for practical applications in biomedicine. The enhanced colloidal stability of the surface modified nanochains is confirmed by Zeta potential (ζ-potential) analysis. Magnetic properties of the nanochains show superparamagnetic state at room temperature since the nanochains are composed of tiny nanoparticles as their building blocks. The measured M(H) data at room temperature have been successfully fitted by the Langevin function and magnetic moment μp = 20,526 μB for sphere-like nanoparticle clusters and μp = 20,767 μB for nanochains are determined. The determined magnetic parameters have revealed that the nanochains show a magnetic moment of the nanoparticles higher than the one of individual nanoparticle clusters. These differences can be attributed to the collective magnetic properties of superparamagnetic iron oxide nanoparticles (SPION) assembled in different morphologies (isotropic and anisotropic morphology). © 2018",
journal = "Materials Characterization",
title = "Synthesis, particle shape characterization, magnetic properties and surface modification of superparamagnetic iron oxide nanochains",
volume = "148",
pages = "123-133",
doi = "10.1016/j.matchar.2018.12.014"
}

Tadić, M., Kralj, S.,& Kopanja, L.. (2019). Synthesis, particle shape characterization, magnetic properties and surface modification of superparamagnetic iron oxide nanochains. in Materials Characterization, 148, 123-133.
https://doi.org/10.1016/j.matchar.2018.12.014

Tadić M, Kralj S, Kopanja L. Synthesis, particle shape characterization, magnetic properties and surface modification of superparamagnetic iron oxide nanochains. in Materials Characterization. 2019;148:123-133.
doi:10.1016/j.matchar.2018.12.014 .

Tadić, Marin, Kralj, Slavko, Kopanja, Lazar, "Synthesis, particle shape characterization, magnetic properties and surface modification of superparamagnetic iron oxide nanochains" in Materials Characterization, 148 (2019):123-133,
https://doi.org/10.1016/j.matchar.2018.12.014 . .

TY  - JOUR
AU  - Kopanja, Lazar
AU  - Tadić, Marin
AU  - Kralj, Slavko
AU  - Žunić, Joviša
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0272884218308812
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7917
AB  - Due to advances in electron microscopy and to the development of novel nanoparticle structures with different morphologies and the dependence of physical properties on the nanoparticle morphology, there is a need for a more precise analysis of nanoparticle structure and morphology. That should provide a simple and unambiguous comparison of nanoparticles' shapes and of material properties that depend on the shape, which has been lacking thus far. Here we study nanochains consisting of silica-coated iron oxide (maghemite, gamma-Fe2O3) nanoparticle clusters covered by an additional layer of silica (core-shell structure). We have developed an algorithm for image segmentation and a quantitative analysis of nanochain shape from real TEM images. To that end we used two distinct measures of circularity and elongation measure (the aspect ratio measure). We show that the relative position and the area of the links, as well as the links' shape lead to significant differences in the measured aspect ratio of the entire nanochain (substantially influence the elongation of nanochains). We have also analyzed the core-shell structures in nanochains, and computed the shell's share in the overall area of observed nanochains. A Matlab code was developed and used for the computation of the elongation measure of shapes appearing in electron microscopy images. Here we have investigated magnetic properties of synthetic nanochains, that revealed superparamagnetic behavior at room temperature (SPION) with the possibility of tuning the magnetization values (approx. from 19 to 46 emu/g). We have compared of magnetization M(H) curves of the anisotropic nanochains and of isotropic nanoparticle (nanochain links), with the conclusion that the nanochains have a higher magnetic susceptibility, which fact can be understood as a consequence of their anisotropic shapes. The nanochains may be applied in biomedicine and magnetic separation, due to their morphology and magnetic properties.
T2  - Ceramics International
T1  - Shape and aspect ratio analysis of anisotropic magnetic nanochains based on TEM micrographs
VL  - 44
IS  - 11
SP  - 12340
EP  - 12351
DO  - 10.1016/j.ceramint.2018.04.021
ER  - 

@article{
author = "Kopanja, Lazar and Tadić, Marin and Kralj, Slavko and Žunić, Joviša",
year = "2018",
abstract = "Due to advances in electron microscopy and to the development of novel nanoparticle structures with different morphologies and the dependence of physical properties on the nanoparticle morphology, there is a need for a more precise analysis of nanoparticle structure and morphology. That should provide a simple and unambiguous comparison of nanoparticles' shapes and of material properties that depend on the shape, which has been lacking thus far. Here we study nanochains consisting of silica-coated iron oxide (maghemite, gamma-Fe2O3) nanoparticle clusters covered by an additional layer of silica (core-shell structure). We have developed an algorithm for image segmentation and a quantitative analysis of nanochain shape from real TEM images. To that end we used two distinct measures of circularity and elongation measure (the aspect ratio measure). We show that the relative position and the area of the links, as well as the links' shape lead to significant differences in the measured aspect ratio of the entire nanochain (substantially influence the elongation of nanochains). We have also analyzed the core-shell structures in nanochains, and computed the shell's share in the overall area of observed nanochains. A Matlab code was developed and used for the computation of the elongation measure of shapes appearing in electron microscopy images. Here we have investigated magnetic properties of synthetic nanochains, that revealed superparamagnetic behavior at room temperature (SPION) with the possibility of tuning the magnetization values (approx. from 19 to 46 emu/g). We have compared of magnetization M(H) curves of the anisotropic nanochains and of isotropic nanoparticle (nanochain links), with the conclusion that the nanochains have a higher magnetic susceptibility, which fact can be understood as a consequence of their anisotropic shapes. The nanochains may be applied in biomedicine and magnetic separation, due to their morphology and magnetic properties.",
journal = "Ceramics International",
title = "Shape and aspect ratio analysis of anisotropic magnetic nanochains based on TEM micrographs",
volume = "44",
number = "11",
pages = "12340-12351",
doi = "10.1016/j.ceramint.2018.04.021"
}

Kopanja, L., Tadić, M., Kralj, S.,& Žunić, J.. (2018). Shape and aspect ratio analysis of anisotropic magnetic nanochains based on TEM micrographs. in Ceramics International, 44(11), 12340-12351.
https://doi.org/10.1016/j.ceramint.2018.04.021

Kopanja L, Tadić M, Kralj S, Žunić J. Shape and aspect ratio analysis of anisotropic magnetic nanochains based on TEM micrographs. in Ceramics International. 2018;44(11):12340-12351.
doi:10.1016/j.ceramint.2018.04.021 .

Kopanja, Lazar, Tadić, Marin, Kralj, Slavko, Žunić, Joviša, "Shape and aspect ratio analysis of anisotropic magnetic nanochains based on TEM micrographs" in Ceramics International, 44, no. 11 (2018):12340-12351,
https://doi.org/10.1016/j.ceramint.2018.04.021 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Milošević, Irena
AU  - Kralj, Slavko
AU  - Mitrić, Miodrag
AU  - Makovec, Darko
AU  - Saboungi, Marie-Louise
AU  - Motte, Laurence
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1662
AB  - We present a simple preparation route to obtain a nanoscale meta-stable hard-magnetic epsilon-Fe2O3 phase, using silica coated beta-FeOOH nanorods as a precursor and an annealing process. The synthesized epsilon-Fe2O3 nanoparticles exhibit large coercivity (H-C similar to 20 kOe at 300 K and H-C similar to 1.6 kOe at 400 K), confirming their high potential for practical applications.
T2  - Nanoscale
T1  - Synthesis of metastable hard-magnetic epsilon-Fe2O3 nanoparticles from silica-coated akaganeite nanorods
VL  - 9
IS  - 30
SP  - 10579
EP  - 10584
DO  - 10.1039/c7nr03639f
ER  - 

@article{
author = "Tadić, Marin and Milošević, Irena and Kralj, Slavko and Mitrić, Miodrag and Makovec, Darko and Saboungi, Marie-Louise and Motte, Laurence",
year = "2017",
abstract = "We present a simple preparation route to obtain a nanoscale meta-stable hard-magnetic epsilon-Fe2O3 phase, using silica coated beta-FeOOH nanorods as a precursor and an annealing process. The synthesized epsilon-Fe2O3 nanoparticles exhibit large coercivity (H-C similar to 20 kOe at 300 K and H-C similar to 1.6 kOe at 400 K), confirming their high potential for practical applications.",
journal = "Nanoscale",
title = "Synthesis of metastable hard-magnetic epsilon-Fe2O3 nanoparticles from silica-coated akaganeite nanorods",
volume = "9",
number = "30",
pages = "10579-10584",
doi = "10.1039/c7nr03639f"
}

Tadić, M., Milošević, I., Kralj, S., Mitrić, M., Makovec, D., Saboungi, M.,& Motte, L.. (2017). Synthesis of metastable hard-magnetic epsilon-Fe2O3 nanoparticles from silica-coated akaganeite nanorods. in Nanoscale, 9(30), 10579-10584.
https://doi.org/10.1039/c7nr03639f

Tadić M, Milošević I, Kralj S, Mitrić M, Makovec D, Saboungi M, Motte L. Synthesis of metastable hard-magnetic epsilon-Fe2O3 nanoparticles from silica-coated akaganeite nanorods. in Nanoscale. 2017;9(30):10579-10584.
doi:10.1039/c7nr03639f .

Tadić, Marin, Milošević, Irena, Kralj, Slavko, Mitrić, Miodrag, Makovec, Darko, Saboungi, Marie-Louise, Motte, Laurence, "Synthesis of metastable hard-magnetic epsilon-Fe2O3 nanoparticles from silica-coated akaganeite nanorods" in Nanoscale, 9, no. 30 (2017):10579-10584,
https://doi.org/10.1039/c7nr03639f . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Kopanja, Lazar
AU  - Panjan, Matjaž
AU  - Kralj, Slavko
AU  - Nikodinović-Runić, Jasmina
AU  - Stojanović, Zoran S.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1449
AB  - Hematite core-shell nanoparticles with plate-like morphology were synthesized using a one-step hydrothermal synthesis. An XRPD analysis indicates that the sample consist of single-phase alpha-Fe2O3 nanoparticles. SEM and TEM measurements show that the hematite sample is composed of uniform core-shell nanoplates with 10-20 nm thickness, 80-100 nm landscape dimensions (aspect ratio 5) and 3-4 nm thickness of the surface shells. We used computational methods for the quantitative analysis of the core-shell particle structure and circularity shape descriptor for the quantitative shape analysis of the nanoparticles from TEM micrographs. The calculated results indicated that a percentage of the shell area in the nanoparticle area (share [%]) is significant. The determined values of circularity in the perpendicular and oblique perspective clearly show shape anisotropy of the nanoplates. The magnetic properties revealed the ferromagnetic-like properties at room temperature with high coercivity H-C = 2340 Oe, pointing to the shape and surface effects. These results signify core-shell hematite nanoparticles for practical applications in magnetic devices. The synthesized hematite plate-like nanoparticles exhibit low cytotoxicity levels on the human lung fibroblasts (MRC5) cell line demonstrating the safe use of these nanoparticles for biomedical applications. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Synthesis of core-shell hematite (alpha-Fe2O3) nanoplates: Quantitative analysis of the particle structure and shape, high coercivity and low cytotoxicity
VL  - 403
SP  - 628
EP  - 634
DO  - 10.1016/j.apsusc.2017.01.115
ER  - 

@article{
author = "Tadić, Marin and Kopanja, Lazar and Panjan, Matjaž and Kralj, Slavko and Nikodinović-Runić, Jasmina and Stojanović, Zoran S.",
year = "2017",
abstract = "Hematite core-shell nanoparticles with plate-like morphology were synthesized using a one-step hydrothermal synthesis. An XRPD analysis indicates that the sample consist of single-phase alpha-Fe2O3 nanoparticles. SEM and TEM measurements show that the hematite sample is composed of uniform core-shell nanoplates with 10-20 nm thickness, 80-100 nm landscape dimensions (aspect ratio 5) and 3-4 nm thickness of the surface shells. We used computational methods for the quantitative analysis of the core-shell particle structure and circularity shape descriptor for the quantitative shape analysis of the nanoparticles from TEM micrographs. The calculated results indicated that a percentage of the shell area in the nanoparticle area (share [%]) is significant. The determined values of circularity in the perpendicular and oblique perspective clearly show shape anisotropy of the nanoplates. The magnetic properties revealed the ferromagnetic-like properties at room temperature with high coercivity H-C = 2340 Oe, pointing to the shape and surface effects. These results signify core-shell hematite nanoparticles for practical applications in magnetic devices. The synthesized hematite plate-like nanoparticles exhibit low cytotoxicity levels on the human lung fibroblasts (MRC5) cell line demonstrating the safe use of these nanoparticles for biomedical applications. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Synthesis of core-shell hematite (alpha-Fe2O3) nanoplates: Quantitative analysis of the particle structure and shape, high coercivity and low cytotoxicity",
volume = "403",
pages = "628-634",
doi = "10.1016/j.apsusc.2017.01.115"
}

Tadić, M., Kopanja, L., Panjan, M., Kralj, S., Nikodinović-Runić, J.,& Stojanović, Z. S.. (2017). Synthesis of core-shell hematite (alpha-Fe2O3) nanoplates: Quantitative analysis of the particle structure and shape, high coercivity and low cytotoxicity. in Applied Surface Science, 403, 628-634.
https://doi.org/10.1016/j.apsusc.2017.01.115

Tadić M, Kopanja L, Panjan M, Kralj S, Nikodinović-Runić J, Stojanović ZS. Synthesis of core-shell hematite (alpha-Fe2O3) nanoplates: Quantitative analysis of the particle structure and shape, high coercivity and low cytotoxicity. in Applied Surface Science. 2017;403:628-634.
doi:10.1016/j.apsusc.2017.01.115 .

Tadić, Marin, Kopanja, Lazar, Panjan, Matjaž, Kralj, Slavko, Nikodinović-Runić, Jasmina, Stojanović, Zoran S., "Synthesis of core-shell hematite (alpha-Fe2O3) nanoplates: Quantitative analysis of the particle structure and shape, high coercivity and low cytotoxicity" in Applied Surface Science, 403 (2017):628-634,
https://doi.org/10.1016/j.apsusc.2017.01.115 . .

TY  - JOUR
AU  - Kopanja, Lazar
AU  - Kralj, Slavko
AU  - Žunić, Dragiša
AU  - Lončar, Boris B.
AU  - Tadić, Marin
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1089
AB  - For the first time, particle shape analysis of silica coated iron oxide (maghemite/magnetite) nanoparticle clusters (core-shell nanostructures) is discussed using computational methods. We analyzed three samples of core-shell nanostructures synthesized with different thickness of the silica shell. A new computational method is presented and successfully applied to the segmentation of the core-shell nanoparticles, as one of the main problems in image analysis of the TEM micrographs. We have introduced the circularity coefficient, marked with k(circ) and defined as the ratio of circularity measure C-2(S) of nanoparticles core and circularity measure core-shell nanoparticles in order to answer the question how the shell affects the overall shape of the final core-shell structure, with respect to circularity. More precisely, the circularity coefficient determines whether the circularity of the core-shell nanoparticle is higher, lower or equal to the circularity of the core. We have also determined the shells share in the overall area of the core-shell nanoparticle. The core-shell nanoparticle clusters here investigated exhibit superparamagnetic properties at room temperature, thus emphasizing their potential for use in practical applications such as in biomedical and particle separation. We show that the saturation magnetization strength can be easily adjusted by controlling the thickness of the silica shell. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
PB  - Elsevier
T2  - Ceramics International
T1  - Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis
VL  - 42
IS  - 9
SP  - 10976
EP  - 10984
DO  - 10.1016/j.ceramint.2016.03.235
ER  - 

@article{
author = "Kopanja, Lazar and Kralj, Slavko and Žunić, Dragiša and Lončar, Boris B. and Tadić, Marin",
year = "2016",
abstract = "For the first time, particle shape analysis of silica coated iron oxide (maghemite/magnetite) nanoparticle clusters (core-shell nanostructures) is discussed using computational methods. We analyzed three samples of core-shell nanostructures synthesized with different thickness of the silica shell. A new computational method is presented and successfully applied to the segmentation of the core-shell nanoparticles, as one of the main problems in image analysis of the TEM micrographs. We have introduced the circularity coefficient, marked with k(circ) and defined as the ratio of circularity measure C-2(S) of nanoparticles core and circularity measure core-shell nanoparticles in order to answer the question how the shell affects the overall shape of the final core-shell structure, with respect to circularity. More precisely, the circularity coefficient determines whether the circularity of the core-shell nanoparticle is higher, lower or equal to the circularity of the core. We have also determined the shells share in the overall area of the core-shell nanoparticle. The core-shell nanoparticle clusters here investigated exhibit superparamagnetic properties at room temperature, thus emphasizing their potential for use in practical applications such as in biomedical and particle separation. We show that the saturation magnetization strength can be easily adjusted by controlling the thickness of the silica shell. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis",
volume = "42",
number = "9",
pages = "10976-10984",
doi = "10.1016/j.ceramint.2016.03.235"
}

Kopanja, L., Kralj, S., Žunić, D., Lončar, B. B.,& Tadić, M.. (2016). Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis. in Ceramics International
Elsevier., 42(9), 10976-10984.
https://doi.org/10.1016/j.ceramint.2016.03.235

Kopanja L, Kralj S, Žunić D, Lončar BB, Tadić M. Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis. in Ceramics International. 2016;42(9):10976-10984.
doi:10.1016/j.ceramint.2016.03.235 .

Kopanja, Lazar, Kralj, Slavko, Žunić, Dragiša, Lončar, Boris B., Tadić, Marin, "Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis" in Ceramics International, 42, no. 9 (2016):10976-10984,
https://doi.org/10.1016/j.ceramint.2016.03.235 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Milošević, Irena
AU  - Kralj, Slavko
AU  - Mbodji, Mamadou
AU  - Motte, Laurence
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/622
AB  - We report on structural and magnetic properties of uniform silica-coated akaganeite nanorods with length of L similar to 80 +/- 15 nm and diameter D similar to 15 +/- 5 nm as well as silica shell thickness of about 5 nm. Unexpected negative difference between field-cooled (FC) and zero-field-cooled (ZFC) magnetization Delta M = M-FC - M-ZFC LT 0, room temperature ferromagnetism, and exchange bias effect have been found. The nanorods are investigated by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) measurements. The magnetic measurements were also performed on bare akaganeite nanorods in order to discriminate the effects of silica coating on the magnetic properties. The measured coercivity and exchange bias effect of bare beta-FeOOH nanorods are much lower compared with same properties of SiO2"beta-FeOOH nanorods, emphasizing the effect of silica coating on the magnetic properties. These results are discussed considering the core shell structure of akaganeite nanorods; i.e., the inner part of the akaganeite nanorod has antiferromagnetic ordering, whereas the nanorod surface exhibits some disorder spin state.
T2  - Journal of Physical Chemistry. C
T1  - Silica-Coated and Bare Akaganeite Nanorods: Structural and Magnetic Properties
VL  - 119
IS  - 24
SP  - 13868
EP  - 13875
DO  - 10.1021/acs.jpcc.5b01547
ER  - 

@article{
author = "Tadić, Marin and Milošević, Irena and Kralj, Slavko and Mbodji, Mamadou and Motte, Laurence",
year = "2015",
abstract = "We report on structural and magnetic properties of uniform silica-coated akaganeite nanorods with length of L similar to 80 +/- 15 nm and diameter D similar to 15 +/- 5 nm as well as silica shell thickness of about 5 nm. Unexpected negative difference between field-cooled (FC) and zero-field-cooled (ZFC) magnetization Delta M = M-FC - M-ZFC LT 0, room temperature ferromagnetism, and exchange bias effect have been found. The nanorods are investigated by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) measurements. The magnetic measurements were also performed on bare akaganeite nanorods in order to discriminate the effects of silica coating on the magnetic properties. The measured coercivity and exchange bias effect of bare beta-FeOOH nanorods are much lower compared with same properties of SiO2"beta-FeOOH nanorods, emphasizing the effect of silica coating on the magnetic properties. These results are discussed considering the core shell structure of akaganeite nanorods; i.e., the inner part of the akaganeite nanorod has antiferromagnetic ordering, whereas the nanorod surface exhibits some disorder spin state.",
journal = "Journal of Physical Chemistry. C",
title = "Silica-Coated and Bare Akaganeite Nanorods: Structural and Magnetic Properties",
volume = "119",
number = "24",
pages = "13868-13875",
doi = "10.1021/acs.jpcc.5b01547"
}

Tadić, M., Milošević, I., Kralj, S., Mbodji, M.,& Motte, L.. (2015). Silica-Coated and Bare Akaganeite Nanorods: Structural and Magnetic Properties. in Journal of Physical Chemistry. C, 119(24), 13868-13875.
https://doi.org/10.1021/acs.jpcc.5b01547

Tadić M, Milošević I, Kralj S, Mbodji M, Motte L. Silica-Coated and Bare Akaganeite Nanorods: Structural and Magnetic Properties. in Journal of Physical Chemistry. C. 2015;119(24):13868-13875.
doi:10.1021/acs.jpcc.5b01547 .

Tadić, Marin, Milošević, Irena, Kralj, Slavko, Mbodji, Mamadou, Motte, Laurence, "Silica-Coated and Bare Akaganeite Nanorods: Structural and Magnetic Properties" in Journal of Physical Chemistry. C, 119, no. 24 (2015):13868-13875,
https://doi.org/10.1021/acs.jpcc.5b01547 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Milošević, Irena
AU  - Kralj, Slavko
AU  - Saboungi, Marie-Louise
AU  - Motte, Laurence
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/532
AB  - We report ferromagnetic-like properties and exchange bias effect in akaganeite (beta-FeOOH) nanorods. They exhibit a Neel temperature T-N = 259 K and ferromagnetic-like hysteresis behavior both below and above T-N. An exchange bias effect is observed below T-N and represents an interesting behavior for akaganeite nanorods. These results are explained on the basis of a core-shell structure in which the core has bulk akaganeite magnetic properties (i.e., antiferromagnetic ordering) while the shell exhibits a disordered spin state. Thus, the nanorods show ferromagnetic properties and an exchange bias effect at the same time, increasing their potential for use in practical applications. (c) 2015 AIP Publishing LLC.
T2  - Applied Physics Letters
T1  - Ferromagnetic behavior and exchange bias effect in akaganeite nanorods
VL  - 106
IS  - 18
DO  - 10.1063/1.4918930
ER  - 

@article{
author = "Tadić, Marin and Milošević, Irena and Kralj, Slavko and Saboungi, Marie-Louise and Motte, Laurence",
year = "2015",
abstract = "We report ferromagnetic-like properties and exchange bias effect in akaganeite (beta-FeOOH) nanorods. They exhibit a Neel temperature T-N = 259 K and ferromagnetic-like hysteresis behavior both below and above T-N. An exchange bias effect is observed below T-N and represents an interesting behavior for akaganeite nanorods. These results are explained on the basis of a core-shell structure in which the core has bulk akaganeite magnetic properties (i.e., antiferromagnetic ordering) while the shell exhibits a disordered spin state. Thus, the nanorods show ferromagnetic properties and an exchange bias effect at the same time, increasing their potential for use in practical applications. (c) 2015 AIP Publishing LLC.",
journal = "Applied Physics Letters",
title = "Ferromagnetic behavior and exchange bias effect in akaganeite nanorods",
volume = "106",
number = "18",
doi = "10.1063/1.4918930"
}

Tadić, M., Milošević, I., Kralj, S., Saboungi, M.,& Motte, L.. (2015). Ferromagnetic behavior and exchange bias effect in akaganeite nanorods. in Applied Physics Letters, 106(18).
https://doi.org/10.1063/1.4918930

Tadić M, Milošević I, Kralj S, Saboungi M, Motte L. Ferromagnetic behavior and exchange bias effect in akaganeite nanorods. in Applied Physics Letters. 2015;106(18).
doi:10.1063/1.4918930 .

Tadić, Marin, Milošević, Irena, Kralj, Slavko, Saboungi, Marie-Louise, Motte, Laurence, "Ferromagnetic behavior and exchange bias effect in akaganeite nanorods" in Applied Physics Letters, 106, no. 18 (2015),
https://doi.org/10.1063/1.4918930 . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Kralj, Slavko
AU  - Jagodič, Marko
AU  - Hanžel, Darko
AU  - Makovec, Darko
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/59
AB  - The aim of this work is to present the magnetic properties of novel superparamagnetic-iNANOvative (TM)vertical bar silica nanoparticle clusters. A TEM analysis showed that these nanoparticle clusters, approximately 80 nm in size, contained an assembly of maghemite nanoparticles in the core and an amorphous silica shell. The maghemite nanoparticles in the core were approximately 10 nm in size, whereas the uniform silica shell was approximately 15-nm thick. The number of magnetic nanoparticles that were densely packed in the core of the single nanocluster was estimated to be approximately 67, resulting in a high magnetic moment for the single nanocluster of m(nc) similar to 1.2 x 10(6) mu(B). This magnetic property of the nanoparticle cluster is advantageous for its easy manipulation using an external magnetic field, for example, in biomedical applications, such as drug delivery, or for magnetic separation in biotechnology. The magnetic properties of the iNANOvative (TM)vertical bar silica nanoparticle clusters were systematically studied, with a special focus on the influence of the magnetic interactions between the nanoparticles in the core. For comparison, the nanoparticle clusters were annealed for 3 h at 300 degrees C in air. The annealing had no influence on the nanoparticles size and phase; however, it had a unique effect on the magnetic properties, i.e., a decrease of the blocking temperature and a weakening of the inter-particle interactions. We believe that this surprising observation is related to the thermal decomposition of the organic surfactant on the surfaces of the nanoparticles at the high annealing temperatures, which resulted in the formation of amorphous carbon inside the nanocluster. (C) 2014 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Magnetic properties of novel superparamagnetic iron oxide nanoclusters and their peculiarity under annealing treatment
VL  - 322
SP  - 255
EP  - 264
DO  - 10.1016/j.apsusc.2014.09.181
ER  - 

@article{
author = "Tadić, Marin and Kralj, Slavko and Jagodič, Marko and Hanžel, Darko and Makovec, Darko",
year = "2014",
abstract = "The aim of this work is to present the magnetic properties of novel superparamagnetic-iNANOvative (TM)vertical bar silica nanoparticle clusters. A TEM analysis showed that these nanoparticle clusters, approximately 80 nm in size, contained an assembly of maghemite nanoparticles in the core and an amorphous silica shell. The maghemite nanoparticles in the core were approximately 10 nm in size, whereas the uniform silica shell was approximately 15-nm thick. The number of magnetic nanoparticles that were densely packed in the core of the single nanocluster was estimated to be approximately 67, resulting in a high magnetic moment for the single nanocluster of m(nc) similar to 1.2 x 10(6) mu(B). This magnetic property of the nanoparticle cluster is advantageous for its easy manipulation using an external magnetic field, for example, in biomedical applications, such as drug delivery, or for magnetic separation in biotechnology. The magnetic properties of the iNANOvative (TM)vertical bar silica nanoparticle clusters were systematically studied, with a special focus on the influence of the magnetic interactions between the nanoparticles in the core. For comparison, the nanoparticle clusters were annealed for 3 h at 300 degrees C in air. The annealing had no influence on the nanoparticles size and phase; however, it had a unique effect on the magnetic properties, i.e., a decrease of the blocking temperature and a weakening of the inter-particle interactions. We believe that this surprising observation is related to the thermal decomposition of the organic surfactant on the surfaces of the nanoparticles at the high annealing temperatures, which resulted in the formation of amorphous carbon inside the nanocluster. (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Magnetic properties of novel superparamagnetic iron oxide nanoclusters and their peculiarity under annealing treatment",
volume = "322",
pages = "255-264",
doi = "10.1016/j.apsusc.2014.09.181"
}

Tadić, M., Kralj, S., Jagodič, M., Hanžel, D.,& Makovec, D.. (2014). Magnetic properties of novel superparamagnetic iron oxide nanoclusters and their peculiarity under annealing treatment. in Applied Surface Science, 322, 255-264.
https://doi.org/10.1016/j.apsusc.2014.09.181

Tadić M, Kralj S, Jagodič M, Hanžel D, Makovec D. Magnetic properties of novel superparamagnetic iron oxide nanoclusters and their peculiarity under annealing treatment. in Applied Surface Science. 2014;322:255-264.
doi:10.1016/j.apsusc.2014.09.181 .

Tadić, Marin, Kralj, Slavko, Jagodič, Marko, Hanžel, Darko, Makovec, Darko, "Magnetic properties of novel superparamagnetic iron oxide nanoclusters and their peculiarity under annealing treatment" in Applied Surface Science, 322 (2014):255-264,
https://doi.org/10.1016/j.apsusc.2014.09.181 . .