Lisjak, Darja

Link to this page

Authority KeyName Variants
orcid::0000-0003-4154-4592
  • Lisjak, Darja (3)
Projects

Author's Bibliography

Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method

Papan, Jelena; Hribar Boštjančič, Patricija; Mertelj, Alenka; Lisjak, Darja

(2021)

TY  - JOUR
AU  - Papan, Jelena
AU  - Hribar Boštjančič, Patricija
AU  - Mertelj, Alenka
AU  - Lisjak, Darja
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9982
AB  - Janus particles, which have two surfaces exhibiting different properties, are promising candidates for various applications. For example, magneto-optic Janus particles could be used for in-vivo cancer imaging, drug delivery, and photothermal therapy. The preparation of such materials on a relatively large scale is challenging, especially if the Janus structure consists of a hard magnetic material like barium hexaferrite nanoplatelets. The focus of this study was to adopt the known Pickering emulsion, i.e., Granick’s method, for the preparation of barium-hexaferrite/gold Janus nanoplatelets. The wax-in-water Pickering emulsions were stabilized with a combination of cetyltrimethyl ammonium bromide and barium hexaferrite nanoplatelets at 80 °C. Colloidosomes of solidified wax covered with the barium hexaferrite nanoplatelets formed after cooling the Pickering emulsions to room temperature. The formation and microstructure of the colloidosomes were thoroughly studied by optical and scanning electron microscopy. The process was optimized by various processing parameters, such as the composition of the emulsion system and the speed and time of emulsification. The colloidosomes with the highest surface coverage were used to prepare the Janus nanoplatelets by decorating the exposed surfaces of the barium hexaferrite nanoplatelets with gold nanospheres using mercaptan chemistry. Transmission electron microscopy was used to inspect the barium-hexaferrite/gold Janus nanoplatelets that were prepared for the first time.
T2  - Nanomaterials
T1  - Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method
VL  - 11
IS  - 11
SP  - 2797
DO  - 10.3390/nano11112797
ER  - 
@article{
author = "Papan, Jelena and Hribar Boštjančič, Patricija and Mertelj, Alenka and Lisjak, Darja",
year = "2021",
abstract = "Janus particles, which have two surfaces exhibiting different properties, are promising candidates for various applications. For example, magneto-optic Janus particles could be used for in-vivo cancer imaging, drug delivery, and photothermal therapy. The preparation of such materials on a relatively large scale is challenging, especially if the Janus structure consists of a hard magnetic material like barium hexaferrite nanoplatelets. The focus of this study was to adopt the known Pickering emulsion, i.e., Granick’s method, for the preparation of barium-hexaferrite/gold Janus nanoplatelets. The wax-in-water Pickering emulsions were stabilized with a combination of cetyltrimethyl ammonium bromide and barium hexaferrite nanoplatelets at 80 °C. Colloidosomes of solidified wax covered with the barium hexaferrite nanoplatelets formed after cooling the Pickering emulsions to room temperature. The formation and microstructure of the colloidosomes were thoroughly studied by optical and scanning electron microscopy. The process was optimized by various processing parameters, such as the composition of the emulsion system and the speed and time of emulsification. The colloidosomes with the highest surface coverage were used to prepare the Janus nanoplatelets by decorating the exposed surfaces of the barium hexaferrite nanoplatelets with gold nanospheres using mercaptan chemistry. Transmission electron microscopy was used to inspect the barium-hexaferrite/gold Janus nanoplatelets that were prepared for the first time.",
journal = "Nanomaterials",
title = "Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method",
volume = "11",
number = "11",
pages = "2797",
doi = "10.3390/nano11112797"
}
Papan, J., Hribar Boštjančič, P., Mertelj, A.,& Lisjak, D.. (2021). Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method. in Nanomaterials, 11(11), 2797.
https://doi.org/10.3390/nano11112797
Papan J, Hribar Boštjančič P, Mertelj A, Lisjak D. Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method. in Nanomaterials. 2021;11(11):2797.
doi:10.3390/nano11112797 .
Papan, Jelena, Hribar Boštjančič, Patricija, Mertelj, Alenka, Lisjak, Darja, "Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method" in Nanomaterials, 11, no. 11 (2021):2797,
https://doi.org/10.3390/nano11112797 . .

Investigation of structural, microstructural and magnetic properties of Yb Y1-F3 solid solutions

Aleksić, Jelena; Barudžija, Tanja; Jugović, Dragana; Mitrić, Miodrag; Bošković, Marko; Jagličić, Zvonko; Lisjak, Darja; Kostić, Ljiljana

(2020)

TY  - JOUR
AU  - Aleksić, Jelena
AU  - Barudžija, Tanja
AU  - Jugović, Dragana
AU  - Mitrić, Miodrag
AU  - Bošković, Marko
AU  - Jagličić, Zvonko
AU  - Lisjak, Darja
AU  - Kostić, Ljiljana
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8858
AB  - In this investigation, we have synthesized YbxY1-xF3 solid solutions by fluorination of yttrium and ytterbium sesquioxides with ammonium hydrogen difluoride. According to the XRD analysis, all synthesized YbxY1-xF3 samples have an orthorhombic crystal structure belonging to the β-YF3 structural type. The refinement of crystal structure was done by the Rietveld method within the Pnma space group using the TCH pseudo-Voigt function. The anisotropic peak broadening was analyzed, and the average apparent crystallite size is about 50 nm with a small anisotropy of shape, while the significant microstrain that is highly anisotropic is present in all samples. The temperature-dependent magnetic susceptibility was analyzed by applying the model of a free ion perturbed by the crystal field. We have obtained the effective magnetic quantum numbers Mieff of four Kramer's doublets of Yb3+ ion along with the entire crystal field splitting of the 2F7/2 manifold of Yb3+ in YF3. The acquired maximum energy splitting of the ground level is about 150 K in our most diluted samples. The field-dependent isothermal magnetization measurements were carried out at various temperatures and analyzed by classical Langevin function. Results obtained from magnetic measurements show that all YbxY1-xF3 (x ≠ 0) solid solutions exhibit pure paramagnetic behavior in the whole temperature range from 2 to 300 K, with a predominant antiferromagnetic exchange interactions. © 2020 Elsevier Ltd
T2  - Journal of Physics and Chemistry of Solids
T1  - Investigation of structural, microstructural and magnetic properties of Yb Y1-F3 solid solutions
VL  - 142
SP  - 109449
DO  - 10.1016/j.jpcs.2020.109449
ER  - 
@article{
author = "Aleksić, Jelena and Barudžija, Tanja and Jugović, Dragana and Mitrić, Miodrag and Bošković, Marko and Jagličić, Zvonko and Lisjak, Darja and Kostić, Ljiljana",
year = "2020",
abstract = "In this investigation, we have synthesized YbxY1-xF3 solid solutions by fluorination of yttrium and ytterbium sesquioxides with ammonium hydrogen difluoride. According to the XRD analysis, all synthesized YbxY1-xF3 samples have an orthorhombic crystal structure belonging to the β-YF3 structural type. The refinement of crystal structure was done by the Rietveld method within the Pnma space group using the TCH pseudo-Voigt function. The anisotropic peak broadening was analyzed, and the average apparent crystallite size is about 50 nm with a small anisotropy of shape, while the significant microstrain that is highly anisotropic is present in all samples. The temperature-dependent magnetic susceptibility was analyzed by applying the model of a free ion perturbed by the crystal field. We have obtained the effective magnetic quantum numbers Mieff of four Kramer's doublets of Yb3+ ion along with the entire crystal field splitting of the 2F7/2 manifold of Yb3+ in YF3. The acquired maximum energy splitting of the ground level is about 150 K in our most diluted samples. The field-dependent isothermal magnetization measurements were carried out at various temperatures and analyzed by classical Langevin function. Results obtained from magnetic measurements show that all YbxY1-xF3 (x ≠ 0) solid solutions exhibit pure paramagnetic behavior in the whole temperature range from 2 to 300 K, with a predominant antiferromagnetic exchange interactions. © 2020 Elsevier Ltd",
journal = "Journal of Physics and Chemistry of Solids",
title = "Investigation of structural, microstructural and magnetic properties of Yb Y1-F3 solid solutions",
volume = "142",
pages = "109449",
doi = "10.1016/j.jpcs.2020.109449"
}
Aleksić, J., Barudžija, T., Jugović, D., Mitrić, M., Bošković, M., Jagličić, Z., Lisjak, D.,& Kostić, L.. (2020). Investigation of structural, microstructural and magnetic properties of Yb Y1-F3 solid solutions. in Journal of Physics and Chemistry of Solids, 142, 109449.
https://doi.org/10.1016/j.jpcs.2020.109449
Aleksić J, Barudžija T, Jugović D, Mitrić M, Bošković M, Jagličić Z, Lisjak D, Kostić L. Investigation of structural, microstructural and magnetic properties of Yb Y1-F3 solid solutions. in Journal of Physics and Chemistry of Solids. 2020;142:109449.
doi:10.1016/j.jpcs.2020.109449 .
Aleksić, Jelena, Barudžija, Tanja, Jugović, Dragana, Mitrić, Miodrag, Bošković, Marko, Jagličić, Zvonko, Lisjak, Darja, Kostić, Ljiljana, "Investigation of structural, microstructural and magnetic properties of Yb Y1-F3 solid solutions" in Journal of Physics and Chemistry of Solids, 142 (2020):109449,
https://doi.org/10.1016/j.jpcs.2020.109449 . .
1

Interference effect between superparamagnetic and spin glass correlated moments in a system of dispersed Co3O4 nanocrystallites

Brankovic, D.; Jokanović, Vukoman R.; Babić-Stojić, Branka S.; Jaglicic, Z.; Lisjak, Darja; Kojić, Dušan

(2009)

TY  - JOUR
AU  - Brankovic, D.
AU  - Jokanović, Vukoman R.
AU  - Babić-Stojić, Branka S.
AU  - Jaglicic, Z.
AU  - Lisjak, Darja
AU  - Kojić, Dušan
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3635
AB  - An inhomogeneous system of aggregates of Co3O4 nanocrystallites dispersed in an amorphous SiO2 matrix has been studied. X-ray diffraction and atomic force microscopy reveal a bimodal distribution of crystallite sizes, smaller nanocrystallites with dimension below 10 nm and larger nanocrystallites of about 20 nm. The Co3O4 nanocrystallites enter the composition of nanograins with dimension 20-60 nm. The nanograins build aggregates with dimension 200-500 nm. A large value of the effective magnetic moment per Co2+ ion obtained from the high-temperature susceptibility measurements indicates possible disturbance of the normal spinel structure in which a fraction of Co3+ ions also possesses magnetic moment. An analysis based on the temperature dependence of the coercive field has shown that the smaller nanocrystallites behave as superparamagnetic particles with a blocking temperature of about 10 K. Simultaneous existence of two relaxation processes is observed in the frequency dependence of the imaginary part of the ac magnetic susceptibility in the vicinity of T = 15.8 K. The temperature dependence of the width of the distribution function of relaxation times obtained from the Cole-Cole diagrams exhibits behaviour characteristic for spin glass dynamics in a temperature range above 17.6 K and is temperature independent below 15.8 K, which is a property of superparamagnetic particles. The variation of the width of the distribution function between 17.6 and 15.8 K indicates that interference of the superparamagnetic and spin glass dynamics occurs. It has been found that average relaxation time increases with decreasing temperature from tau(c) LT 10(-4) s at 17.6 K to 1.5 x 10(-1) s at 15 K. The increase of the average relaxation time with decreasing temperature, the observed blocking temperature of the superparamagnetic moments at about 10 K and interference appearing between the two spin dynamics suggest that the magnetic moments in the smaller as well as in the larger nanocrystallites are subject to a thermally activated blocking process at low temperatures.
T2  - Journal of Physics: Condensed Matter
T1  - Interference effect between superparamagnetic and spin glass correlated moments in a system of dispersed Co3O4 nanocrystallites
VL  - 21
IS  - 9
DO  - 10.1088/0953-8984/21/9/095303
ER  - 
@article{
author = "Brankovic, D. and Jokanović, Vukoman R. and Babić-Stojić, Branka S. and Jaglicic, Z. and Lisjak, Darja and Kojić, Dušan",
year = "2009",
abstract = "An inhomogeneous system of aggregates of Co3O4 nanocrystallites dispersed in an amorphous SiO2 matrix has been studied. X-ray diffraction and atomic force microscopy reveal a bimodal distribution of crystallite sizes, smaller nanocrystallites with dimension below 10 nm and larger nanocrystallites of about 20 nm. The Co3O4 nanocrystallites enter the composition of nanograins with dimension 20-60 nm. The nanograins build aggregates with dimension 200-500 nm. A large value of the effective magnetic moment per Co2+ ion obtained from the high-temperature susceptibility measurements indicates possible disturbance of the normal spinel structure in which a fraction of Co3+ ions also possesses magnetic moment. An analysis based on the temperature dependence of the coercive field has shown that the smaller nanocrystallites behave as superparamagnetic particles with a blocking temperature of about 10 K. Simultaneous existence of two relaxation processes is observed in the frequency dependence of the imaginary part of the ac magnetic susceptibility in the vicinity of T = 15.8 K. The temperature dependence of the width of the distribution function of relaxation times obtained from the Cole-Cole diagrams exhibits behaviour characteristic for spin glass dynamics in a temperature range above 17.6 K and is temperature independent below 15.8 K, which is a property of superparamagnetic particles. The variation of the width of the distribution function between 17.6 and 15.8 K indicates that interference of the superparamagnetic and spin glass dynamics occurs. It has been found that average relaxation time increases with decreasing temperature from tau(c) LT 10(-4) s at 17.6 K to 1.5 x 10(-1) s at 15 K. The increase of the average relaxation time with decreasing temperature, the observed blocking temperature of the superparamagnetic moments at about 10 K and interference appearing between the two spin dynamics suggest that the magnetic moments in the smaller as well as in the larger nanocrystallites are subject to a thermally activated blocking process at low temperatures.",
journal = "Journal of Physics: Condensed Matter",
title = "Interference effect between superparamagnetic and spin glass correlated moments in a system of dispersed Co3O4 nanocrystallites",
volume = "21",
number = "9",
doi = "10.1088/0953-8984/21/9/095303"
}
Brankovic, D., Jokanović, V. R., Babić-Stojić, B. S., Jaglicic, Z., Lisjak, D.,& Kojić, D.. (2009). Interference effect between superparamagnetic and spin glass correlated moments in a system of dispersed Co3O4 nanocrystallites. in Journal of Physics: Condensed Matter, 21(9).
https://doi.org/10.1088/0953-8984/21/9/095303
Brankovic D, Jokanović VR, Babić-Stojić BS, Jaglicic Z, Lisjak D, Kojić D. Interference effect between superparamagnetic and spin glass correlated moments in a system of dispersed Co3O4 nanocrystallites. in Journal of Physics: Condensed Matter. 2009;21(9).
doi:10.1088/0953-8984/21/9/095303 .
Brankovic, D., Jokanović, Vukoman R., Babić-Stojić, Branka S., Jaglicic, Z., Lisjak, Darja, Kojić, Dušan, "Interference effect between superparamagnetic and spin glass correlated moments in a system of dispersed Co3O4 nanocrystallites" in Journal of Physics: Condensed Matter, 21, no. 9 (2009),
https://doi.org/10.1088/0953-8984/21/9/095303 . .
11
9
10