TY  - JOUR
AU  - Muscas, Giuseppe
AU  - Jovanović, Sonja
AU  - Vukomanović, Marija
AU  - Spreitzer, Matjaž
AU  - Peddis, Davide
PY  - 2019
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0925838819316147
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8194
AB  - Magnetic nanoparticles represent complex but very interesting objects. They combine the bulk properties with novel phenomena emerging at the nanoscale due to finite-size effects. The recent development of the synthetic procedures allows having a strong control on the size and shape of individual particles and on their physical-chemical structure. Among different magnetic materials, spinel ferrite nanoparticles offer strong chemical and physical stability as well as tunable magnetic properties. In the present article, we investigate the effect of Zn substitution in cobalt ferrite nanoparticles. The technological development of nanoparticle-based magnetic materials aims to find a balance between a well-defined magnetic behavior of individual elements and their strong interactions, which arise from the need of miniaturization that leads to dense ensembles of the system's constituents. Within this complex context, we provide one route to optimize the properties of small spinel ferrite particles by tuning their chemical composition without compromise their structural properties, and with full control of their size and shape. Furthermore, we propose an advanced analysis of their magnetic properties in the framework of the random anisotropy model. We will show that the chemical composition not only determines the intrinsic anisotropy energy of each nanoparticle but also owns a profound effect on the interparticle interactions. © 2019 Elsevier B.V.
T2  - Journal of Alloys and Compounds
T1  - Zn-doped cobalt ferrite: Tuning the interactions by chemical composition
VL  - 796
SP  - 203
EP  - 209
DO  - 10.1016/j.jallcom.2019.04.308
ER  - 

@article{
author = "Muscas, Giuseppe and Jovanović, Sonja and Vukomanović, Marija and Spreitzer, Matjaž and Peddis, Davide",
year = "2019",
abstract = "Magnetic nanoparticles represent complex but very interesting objects. They combine the bulk properties with novel phenomena emerging at the nanoscale due to finite-size effects. The recent development of the synthetic procedures allows having a strong control on the size and shape of individual particles and on their physical-chemical structure. Among different magnetic materials, spinel ferrite nanoparticles offer strong chemical and physical stability as well as tunable magnetic properties. In the present article, we investigate the effect of Zn substitution in cobalt ferrite nanoparticles. The technological development of nanoparticle-based magnetic materials aims to find a balance between a well-defined magnetic behavior of individual elements and their strong interactions, which arise from the need of miniaturization that leads to dense ensembles of the system's constituents. Within this complex context, we provide one route to optimize the properties of small spinel ferrite particles by tuning their chemical composition without compromise their structural properties, and with full control of their size and shape. Furthermore, we propose an advanced analysis of their magnetic properties in the framework of the random anisotropy model. We will show that the chemical composition not only determines the intrinsic anisotropy energy of each nanoparticle but also owns a profound effect on the interparticle interactions. © 2019 Elsevier B.V.",
journal = "Journal of Alloys and Compounds",
title = "Zn-doped cobalt ferrite: Tuning the interactions by chemical composition",
volume = "796",
pages = "203-209",
doi = "10.1016/j.jallcom.2019.04.308"
}

Muscas, G., Jovanović, S., Vukomanović, M., Spreitzer, M.,& Peddis, D.. (2019). Zn-doped cobalt ferrite: Tuning the interactions by chemical composition. in Journal of Alloys and Compounds, 796, 203-209.
https://doi.org/10.1016/j.jallcom.2019.04.308

Muscas G, Jovanović S, Vukomanović M, Spreitzer M, Peddis D. Zn-doped cobalt ferrite: Tuning the interactions by chemical composition. in Journal of Alloys and Compounds. 2019;796:203-209.
doi:10.1016/j.jallcom.2019.04.308 .

Muscas, Giuseppe, Jovanović, Sonja, Vukomanović, Marija, Spreitzer, Matjaž, Peddis, Davide, "Zn-doped cobalt ferrite: Tuning the interactions by chemical composition" in Journal of Alloys and Compounds, 796 (2019):203-209,
https://doi.org/10.1016/j.jallcom.2019.04.308 . .

TY  - JOUR
AU  - Concas, Giorgio
AU  - Congiu, Francesco
AU  - Muscas, Giuseppe
AU  - Peddis, Davide
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1674
AB  - We studied the temperature,dependence of the magnetization in an ensemble of monodomain nanoparticles both with dc magnetometry and Mossbauer spectroscopy. The analytical form of the temperature dependence is given by the complementary cumulative distribution function. This allows to determine the magnetization blocking temperatures of the sample by a fitting procedure. It is possible to calculate the Mossbauer blocking temperature by a single spectrum and the dc magnetization blocking temperature by, two points of the thermoremanent magnetization curve, thus with a large reduction of the experimental work. The method may be used for particles with not too strong interactions, such happens in the Fe28 sample and not for samples with strong interactions as N30; it may be used for interparticle interaction energies up to 2 yJ and not for energies larger than 60 yJ. This method of analysis of the data should be used in the future work concerning the thermoremanent magnetization and Mossbauer spectra of magnetic nanoparticles.
T2  - Journal of Physical Chemistry. C
T1  - Determination of Blocking Temperature in Magnetization and Mossbauer Time Scale: A Functional Form Approach
VL  - 121
IS  - 30
SP  - 16541
EP  - 16548
DO  - 10.1021/acs.jpcc.7b01748
ER  - 

@article{
author = "Concas, Giorgio and Congiu, Francesco and Muscas, Giuseppe and Peddis, Davide",
year = "2017",
abstract = "We studied the temperature,dependence of the magnetization in an ensemble of monodomain nanoparticles both with dc magnetometry and Mossbauer spectroscopy. The analytical form of the temperature dependence is given by the complementary cumulative distribution function. This allows to determine the magnetization blocking temperatures of the sample by a fitting procedure. It is possible to calculate the Mossbauer blocking temperature by a single spectrum and the dc magnetization blocking temperature by, two points of the thermoremanent magnetization curve, thus with a large reduction of the experimental work. The method may be used for particles with not too strong interactions, such happens in the Fe28 sample and not for samples with strong interactions as N30; it may be used for interparticle interaction energies up to 2 yJ and not for energies larger than 60 yJ. This method of analysis of the data should be used in the future work concerning the thermoremanent magnetization and Mossbauer spectra of magnetic nanoparticles.",
journal = "Journal of Physical Chemistry. C",
title = "Determination of Blocking Temperature in Magnetization and Mossbauer Time Scale: A Functional Form Approach",
volume = "121",
number = "30",
pages = "16541-16548",
doi = "10.1021/acs.jpcc.7b01748"
}

Concas, G., Congiu, F., Muscas, G.,& Peddis, D.. (2017). Determination of Blocking Temperature in Magnetization and Mossbauer Time Scale: A Functional Form Approach. in Journal of Physical Chemistry. C, 121(30), 16541-16548.
https://doi.org/10.1021/acs.jpcc.7b01748

Concas G, Congiu F, Muscas G, Peddis D. Determination of Blocking Temperature in Magnetization and Mossbauer Time Scale: A Functional Form Approach. in Journal of Physical Chemistry. C. 2017;121(30):16541-16548.
doi:10.1021/acs.jpcc.7b01748 .

Concas, Giorgio, Congiu, Francesco, Muscas, Giuseppe, Peddis, Davide, "Determination of Blocking Temperature in Magnetization and Mossbauer Time Scale: A Functional Form Approach" in Journal of Physical Chemistry. C, 121, no. 30 (2017):16541-16548,
https://doi.org/10.1021/acs.jpcc.7b01748 . .

TY  - JOUR
AU  - Peddis, Davide
AU  - Muscas, Giuseppe
AU  - Mathieu, R.
AU  - Kumar, P. Anil
AU  - Varvaro, Gaspare
AU  - Singh, G.
AU  - Orue, I.
AU  - Gil-Carton, D.
AU  - Marcano, L.
AU  - Muela, A.
AU  - Fdez-Gubieda, M. L.
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1272
AB  - Magnetic nanoparticles (MNPs) are widely investigated due to their potential use in various applications, ranging from electronics to biomedical devices. The magnetic properties of MNPs are strongly dependent on their size and shape (i.e., morphology), thus appropriate tools to investigate their morphology are fundamental to understand the physics of these systems. Recently a new approach to study nanoparticle morphology by Transmission Electron Microscopy (TEM) analysis has been proposed, introducing the so-called Aspect Maps (AMs). In this paper, a further evolution of the AM method is presented, allowing determination of the nanoparticles 3D shape by TEM image. As a case study, this paper will focus on magnetite nanoparticles (Fe3O4), with a mean size of similar to 45 nm extracted from Magnetospirillum gryphiswaldense magnetostatic bacteria (MTB). The proposed approach gives a complete description of the nanoparticles morphology, allowing estimation of an average geometrical size and shape. In addition, preliminary investigation of the magnetic properties of MTB nanoparticles was performed, giving some insight into interparticle interactions and on the reversal mechanism of the magnetization.
T2  - Faraday Discussions
T1  - Studying nanoparticles 3D shape by aspect maps: Determination of the morphology of bacterial magnetic nanoparticles
VL  - 191
SP  - 177
EP  - 188
DO  - 10.1039/c6fd00059b
ER  - 

@article{
author = "Peddis, Davide and Muscas, Giuseppe and Mathieu, R. and Kumar, P. Anil and Varvaro, Gaspare and Singh, G. and Orue, I. and Gil-Carton, D. and Marcano, L. and Muela, A. and Fdez-Gubieda, M. L.",
year = "2016",
abstract = "Magnetic nanoparticles (MNPs) are widely investigated due to their potential use in various applications, ranging from electronics to biomedical devices. The magnetic properties of MNPs are strongly dependent on their size and shape (i.e., morphology), thus appropriate tools to investigate their morphology are fundamental to understand the physics of these systems. Recently a new approach to study nanoparticle morphology by Transmission Electron Microscopy (TEM) analysis has been proposed, introducing the so-called Aspect Maps (AMs). In this paper, a further evolution of the AM method is presented, allowing determination of the nanoparticles 3D shape by TEM image. As a case study, this paper will focus on magnetite nanoparticles (Fe3O4), with a mean size of similar to 45 nm extracted from Magnetospirillum gryphiswaldense magnetostatic bacteria (MTB). The proposed approach gives a complete description of the nanoparticles morphology, allowing estimation of an average geometrical size and shape. In addition, preliminary investigation of the magnetic properties of MTB nanoparticles was performed, giving some insight into interparticle interactions and on the reversal mechanism of the magnetization.",
journal = "Faraday Discussions",
title = "Studying nanoparticles 3D shape by aspect maps: Determination of the morphology of bacterial magnetic nanoparticles",
volume = "191",
pages = "177-188",
doi = "10.1039/c6fd00059b"
}

Peddis, D., Muscas, G., Mathieu, R., Kumar, P. A., Varvaro, G., Singh, G., Orue, I., Gil-Carton, D., Marcano, L., Muela, A.,& Fdez-Gubieda, M. L.. (2016). Studying nanoparticles 3D shape by aspect maps: Determination of the morphology of bacterial magnetic nanoparticles. in Faraday Discussions, 191, 177-188.
https://doi.org/10.1039/c6fd00059b

Peddis D, Muscas G, Mathieu R, Kumar PA, Varvaro G, Singh G, Orue I, Gil-Carton D, Marcano L, Muela A, Fdez-Gubieda ML. Studying nanoparticles 3D shape by aspect maps: Determination of the morphology of bacterial magnetic nanoparticles. in Faraday Discussions. 2016;191:177-188.
doi:10.1039/c6fd00059b .

Peddis, Davide, Muscas, Giuseppe, Mathieu, R., Kumar, P. Anil, Varvaro, Gaspare, Singh, G., Orue, I., Gil-Carton, D., Marcano, L., Muela, A., Fdez-Gubieda, M. L., "Studying nanoparticles 3D shape by aspect maps: Determination of the morphology of bacterial magnetic nanoparticles" in Faraday Discussions, 191 (2016):177-188,
https://doi.org/10.1039/c6fd00059b . .