TY  - JOUR
AU  - Koltunowicz, T. N.
AU  - Zukowski, P.
AU  - Milosavljević, Momir
AU  - Saad, A. M.
AU  - Kasiuk, J. V.
AU  - Fedotova, J. A.
AU  - Kalinin, Yu E.
AU  - Sitnikov, A. V.
AU  - Fedotov, A. K.
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5788
AB  - The present paper investigates dependencies of DC/AC conductances on metallic-to-dielectric phase ratio x, temperature T and frequency f in granular nanocomposite films containing FeCoZr nanoparticles embedded into oxygen-free CaF2 matrix. The specific admittance/conductance dependences on x/T/f for the studied films around the percolation configuration was found to be in agreement with their phase structure which was strongly dependent on the composition of gas atmosphere at deposition. The character of temperature/frequency dependences of AC/DC conductance indicates the predominance of electron tunneling (hopping) over the barriers between metallic nanoparticles in carrier transport. (C) 2012 Elsevier B. V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - AC/DC conductance in granular nanocomposite films (Fe45Co45Zr10)(x)(CaF2)(100-x)
VL  - 586
SP  - S353
EP  - S356
DO  - 10.1016/j.jallcom.2012.09.121
ER  - 

@article{
author = "Koltunowicz, T. N. and Zukowski, P. and Milosavljević, Momir and Saad, A. M. and Kasiuk, J. V. and Fedotova, J. A. and Kalinin, Yu E. and Sitnikov, A. V. and Fedotov, A. K.",
year = "2014",
abstract = "The present paper investigates dependencies of DC/AC conductances on metallic-to-dielectric phase ratio x, temperature T and frequency f in granular nanocomposite films containing FeCoZr nanoparticles embedded into oxygen-free CaF2 matrix. The specific admittance/conductance dependences on x/T/f for the studied films around the percolation configuration was found to be in agreement with their phase structure which was strongly dependent on the composition of gas atmosphere at deposition. The character of temperature/frequency dependences of AC/DC conductance indicates the predominance of electron tunneling (hopping) over the barriers between metallic nanoparticles in carrier transport. (C) 2012 Elsevier B. V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "AC/DC conductance in granular nanocomposite films (Fe45Co45Zr10)(x)(CaF2)(100-x)",
volume = "586",
pages = "S353-S356",
doi = "10.1016/j.jallcom.2012.09.121"
}

Koltunowicz, T. N., Zukowski, P., Milosavljević, M., Saad, A. M., Kasiuk, J. V., Fedotova, J. A., Kalinin, Y. E., Sitnikov, A. V.,& Fedotov, A. K.. (2014). AC/DC conductance in granular nanocomposite films (Fe45Co45Zr10)(x)(CaF2)(100-x). in Journal of Alloys and Compounds, 586, S353-S356.
https://doi.org/10.1016/j.jallcom.2012.09.121

Koltunowicz TN, Zukowski P, Milosavljević M, Saad AM, Kasiuk JV, Fedotova JA, Kalinin YE, Sitnikov AV, Fedotov AK. AC/DC conductance in granular nanocomposite films (Fe45Co45Zr10)(x)(CaF2)(100-x). in Journal of Alloys and Compounds. 2014;586:S353-S356.
doi:10.1016/j.jallcom.2012.09.121 .

Koltunowicz, T. N., Zukowski, P., Milosavljević, Momir, Saad, A. M., Kasiuk, J. V., Fedotova, J. A., Kalinin, Yu E., Sitnikov, A. V., Fedotov, A. K., "AC/DC conductance in granular nanocomposite films (Fe45Co45Zr10)(x)(CaF2)(100-x)" in Journal of Alloys and Compounds, 586 (2014):S353-S356,
https://doi.org/10.1016/j.jallcom.2012.09.121 . .

TY  - JOUR
AU  - Svito, I.
AU  - Fedotova, J. A.
AU  - Milosavljević, Momir
AU  - Zhukowski, P.
AU  - Koltunowicz, T. N.
AU  - Saad, A.
AU  - Kierczynski, Konrad
AU  - Fedotov, A. K.
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7039
AB  - The present paper investigates conductivity sigma for a wide temperature range of 2 K LT T LT 300 K in the nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films (1-6 mu m thicknesses, 0.30 LT x LT 1.00) which were sputtered on glass-ceramic substrates from the compound target in vacuum chamber filled with Ar (set 1 films) or Ar + O-2 gas mixture (set 2 films). TEM and HRTEM images revealed that granular films of set 1 containing nanosized crystalline metallic bcc alpha-FeCo-based nanoparticles embedded in the amorphous Al2O3 matrix. In case of Ar + O atmosphere of deposited alpha-FeCo-based crystalline cores with stabilized sizes were covered with an amorphous FeCo-based oxide shells. The sigma(T) dependences were found to be in agreement with this phase structure. They show transition of the set 1 films sigma(T) curves with x from tunneling (hopping) behavior below the percolation threshold x LT x(c) approximate to 0.46 to metallic one for x GT x(c). Moreover, as opposed to such behavior, for the set 2 films hopping mechanism of sigma(T) was revealed far beyond x(c) due to the formation of semiconducting FeCo-based oxide shells separating electrically contacting FeCoZr cores. (C) 2013 Elsevier B.V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - Influence of sputtering atmosphere on hopping conductance in granular nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films
VL  - 615
SP  - S344
EP  - S347
DO  - 10.1016/j.jallcom.2013.12.061
ER  - 

@article{
author = "Svito, I. and Fedotova, J. A. and Milosavljević, Momir and Zhukowski, P. and Koltunowicz, T. N. and Saad, A. and Kierczynski, Konrad and Fedotov, A. K.",
year = "2014",
abstract = "The present paper investigates conductivity sigma for a wide temperature range of 2 K LT T LT 300 K in the nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films (1-6 mu m thicknesses, 0.30 LT x LT 1.00) which were sputtered on glass-ceramic substrates from the compound target in vacuum chamber filled with Ar (set 1 films) or Ar + O-2 gas mixture (set 2 films). TEM and HRTEM images revealed that granular films of set 1 containing nanosized crystalline metallic bcc alpha-FeCo-based nanoparticles embedded in the amorphous Al2O3 matrix. In case of Ar + O atmosphere of deposited alpha-FeCo-based crystalline cores with stabilized sizes were covered with an amorphous FeCo-based oxide shells. The sigma(T) dependences were found to be in agreement with this phase structure. They show transition of the set 1 films sigma(T) curves with x from tunneling (hopping) behavior below the percolation threshold x LT x(c) approximate to 0.46 to metallic one for x GT x(c). Moreover, as opposed to such behavior, for the set 2 films hopping mechanism of sigma(T) was revealed far beyond x(c) due to the formation of semiconducting FeCo-based oxide shells separating electrically contacting FeCoZr cores. (C) 2013 Elsevier B.V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "Influence of sputtering atmosphere on hopping conductance in granular nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films",
volume = "615",
pages = "S344-S347",
doi = "10.1016/j.jallcom.2013.12.061"
}

Svito, I., Fedotova, J. A., Milosavljević, M., Zhukowski, P., Koltunowicz, T. N., Saad, A., Kierczynski, K.,& Fedotov, A. K.. (2014). Influence of sputtering atmosphere on hopping conductance in granular nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films. in Journal of Alloys and Compounds, 615, S344-S347.
https://doi.org/10.1016/j.jallcom.2013.12.061

Svito I, Fedotova JA, Milosavljević M, Zhukowski P, Koltunowicz TN, Saad A, Kierczynski K, Fedotov AK. Influence of sputtering atmosphere on hopping conductance in granular nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films. in Journal of Alloys and Compounds. 2014;615:S344-S347.
doi:10.1016/j.jallcom.2013.12.061 .

Svito, I., Fedotova, J. A., Milosavljević, Momir, Zhukowski, P., Koltunowicz, T. N., Saad, A., Kierczynski, Konrad, Fedotov, A. K., "Influence of sputtering atmosphere on hopping conductance in granular nanocomposite (FeCoZr)(x)(Al2O3)(1-x) films" in Journal of Alloys and Compounds, 615 (2014):S344-S347,
https://doi.org/10.1016/j.jallcom.2013.12.061 . .

TY  - JOUR
AU  - Koltunowicz, T. N.
AU  - Zhukowski, P.
AU  - Bondariev, V.
AU  - Saad, A.
AU  - Fedotova, J. A.
AU  - Fedotov, A. K.
AU  - Milosavljević, Momir
AU  - Kasiuk, J. V.
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7040
AB  - The paper presents frequency f and temperature T-p dependences of phase shift angle Theta, admittance sigma and capacitance C-p for the as-deposited and annealed (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion-beam sputtering of a compound target in a mixed argon-oxygen gas atmosphere in vacuum chamber. The studied films presented metallic FeCoZr cores covered with FeCo-based oxide shells embedded into oxygen-free dielectric matrix (fluorite). It was found for the metallic phase content within the range of 52.2 at.% LT = x LT = 84.3 at.% in low-f region that Theta values were negative, while in the high-f region we observed the Theta LT 0 degrees. It was obtained that the f-dependences of capacitance module displayed minimum at the corresponding frequency when the Theta(f) crossed its zero line Theta = 0 degrees. It was also observed that the sigma(T-p) dependence displayed the occurrence of two minima that were related to the values of Theta(1) = 90 degrees (the first minimum) and of Theta(2)= -90 degrees (the second one). Some possible reasons of such behavior of (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films are discussed. (C) 2013 Elsevier B.V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - Enhancement of negative capacitance effect in (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere
VL  - 615
SP  - S361
EP  - S365
DO  - 10.1016/j.jallcom.2013.12.125
ER  - 

@article{
author = "Koltunowicz, T. N. and Zhukowski, P. and Bondariev, V. and Saad, A. and Fedotova, J. A. and Fedotov, A. K. and Milosavljević, Momir and Kasiuk, J. V.",
year = "2014",
abstract = "The paper presents frequency f and temperature T-p dependences of phase shift angle Theta, admittance sigma and capacitance C-p for the as-deposited and annealed (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion-beam sputtering of a compound target in a mixed argon-oxygen gas atmosphere in vacuum chamber. The studied films presented metallic FeCoZr cores covered with FeCo-based oxide shells embedded into oxygen-free dielectric matrix (fluorite). It was found for the metallic phase content within the range of 52.2 at.% LT = x LT = 84.3 at.% in low-f region that Theta values were negative, while in the high-f region we observed the Theta LT 0 degrees. It was obtained that the f-dependences of capacitance module displayed minimum at the corresponding frequency when the Theta(f) crossed its zero line Theta = 0 degrees. It was also observed that the sigma(T-p) dependence displayed the occurrence of two minima that were related to the values of Theta(1) = 90 degrees (the first minimum) and of Theta(2)= -90 degrees (the second one). Some possible reasons of such behavior of (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films are discussed. (C) 2013 Elsevier B.V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "Enhancement of negative capacitance effect in (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere",
volume = "615",
pages = "S361-S365",
doi = "10.1016/j.jallcom.2013.12.125"
}

Koltunowicz, T. N., Zhukowski, P., Bondariev, V., Saad, A., Fedotova, J. A., Fedotov, A. K., Milosavljević, M.,& Kasiuk, J. V.. (2014). Enhancement of negative capacitance effect in (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere. in Journal of Alloys and Compounds, 615, S361-S365.
https://doi.org/10.1016/j.jallcom.2013.12.125

Koltunowicz TN, Zhukowski P, Bondariev V, Saad A, Fedotova JA, Fedotov AK, Milosavljević M, Kasiuk JV. Enhancement of negative capacitance effect in (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere. in Journal of Alloys and Compounds. 2014;615:S361-S365.
doi:10.1016/j.jallcom.2013.12.125 .

Koltunowicz, T. N., Zhukowski, P., Bondariev, V., Saad, A., Fedotova, J. A., Fedotov, A. K., Milosavljević, Momir, Kasiuk, J. V., "Enhancement of negative capacitance effect in (CoFeZr)(x)(CaF2)((100-x)) nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere" in Journal of Alloys and Compounds, 615 (2014):S361-S365,
https://doi.org/10.1016/j.jallcom.2013.12.125 . .