TY  - JOUR
AU  - Jokanović, Vukoman R.
AU  - Mioč, Ubavka B.
AU  - Nedić, Zoran
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6560
AB  - Ultrasonic spray pyrolysis has been used to obtain fine spherical powders of WPA bronzes from a 29-tungstenphosphoric acid (WPA-29) feed solution. The average grain size of the obtained powder particles is ca. 1000 nm; these consist of subparticles in the 30-80 run range. The experimentally determined average WPA bronze particle size values are compared with theoretically calculated ones; fairly good agreement between them is found. It is also shown that the average grain size and grain size distribution of the structure and substructure of the obtained powder are predictable. (c) 2005 Elsevier B.V. All rights reserved.
T2  - Solid State Ionics
T1  - Nanostructured phosphorous tungsten bronzes from ultrasonic spray pyrolysis
VL  - 176
IS  - 39-40
SP  - 2955
EP  - 2956
DO  - 10.1016/j.ssi.2005.09.029
ER  - 

@article{
author = "Jokanović, Vukoman R. and Mioč, Ubavka B. and Nedić, Zoran",
year = "2005",
abstract = "Ultrasonic spray pyrolysis has been used to obtain fine spherical powders of WPA bronzes from a 29-tungstenphosphoric acid (WPA-29) feed solution. The average grain size of the obtained powder particles is ca. 1000 nm; these consist of subparticles in the 30-80 run range. The experimentally determined average WPA bronze particle size values are compared with theoretically calculated ones; fairly good agreement between them is found. It is also shown that the average grain size and grain size distribution of the structure and substructure of the obtained powder are predictable. (c) 2005 Elsevier B.V. All rights reserved.",
journal = "Solid State Ionics",
title = "Nanostructured phosphorous tungsten bronzes from ultrasonic spray pyrolysis",
volume = "176",
number = "39-40",
pages = "2955-2956",
doi = "10.1016/j.ssi.2005.09.029"
}

Jokanović, V. R., Mioč, U. B.,& Nedić, Z.. (2005). Nanostructured phosphorous tungsten bronzes from ultrasonic spray pyrolysis. in Solid State Ionics, 176(39-40), 2955-2956.
https://doi.org/10.1016/j.ssi.2005.09.029

Jokanović VR, Mioč UB, Nedić Z. Nanostructured phosphorous tungsten bronzes from ultrasonic spray pyrolysis. in Solid State Ionics. 2005;176(39-40):2955-2956.
doi:10.1016/j.ssi.2005.09.029 .

Jokanović, Vukoman R., Mioč, Ubavka B., Nedić, Zoran, "Nanostructured phosphorous tungsten bronzes from ultrasonic spray pyrolysis" in Solid State Ionics, 176, no. 39-40 (2005):2955-2956,
https://doi.org/10.1016/j.ssi.2005.09.029 . .

TY  - JOUR
AU  - Davidovic, A
AU  - Cajkovski, T
AU  - Colomban, P
AU  - Mioč, Ubavka B.
AU  - Likar-Smiljanic, V
AU  - Cajkovski, D
AU  - Biljic, R
AU  - Nedić, Zoran
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6559
AB  - The effect of monovalent and bivalent cations on some electrical properties of 12-tungstophosphoric acid (WPA) salts were studied. The charge carriers in this acid are protonic entities such as H+, OH- and various forms of hydrated proton H(H2O)(n)(+). Conductivity, dielectric relaxations and activation energies of WPA were investigated. Permittivity measurements were performed on pressed polycrystalline pellets at lower frequencies (5 Hz-500 kHz) and in the X-band microwave range (8-12 GHz); the temperature interval was from room temperature to 360 K. In the microwave region, WPA hexahydrate (WPA-6) and some IATA salts exhibit one, two or three relaxations of the Debye type. Their relaxation times of the order of 10(-11) s are attributed to the fast reorientation of water molecules and/or fast reorientation of oxonium ions (H3O+). In the lower frequency interval, dielectric relaxations of WPA-6 and some IATA salts with longer relaxation times of the order of 10(-7)-10(-5) s were registered and assigned to ion (H+ and/or H3O+) and cation jumps. (c) 2005 Elsevier B.V. All rights reserved.
T2  - Solid State Ionics
T1  - The influence of monovalent and bivalent cations on the electrical properties of 12-Tungstophosphoric acid salts
VL  - 176
IS  - 39-40
SP  - 2881
EP  - 2885
DO  - 10.1016/j.ssi.2005.09.020
ER  - 

@article{
author = "Davidovic, A and Cajkovski, T and Colomban, P and Mioč, Ubavka B. and Likar-Smiljanic, V and Cajkovski, D and Biljic, R and Nedić, Zoran",
year = "2005",
abstract = "The effect of monovalent and bivalent cations on some electrical properties of 12-tungstophosphoric acid (WPA) salts were studied. The charge carriers in this acid are protonic entities such as H+, OH- and various forms of hydrated proton H(H2O)(n)(+). Conductivity, dielectric relaxations and activation energies of WPA were investigated. Permittivity measurements were performed on pressed polycrystalline pellets at lower frequencies (5 Hz-500 kHz) and in the X-band microwave range (8-12 GHz); the temperature interval was from room temperature to 360 K. In the microwave region, WPA hexahydrate (WPA-6) and some IATA salts exhibit one, two or three relaxations of the Debye type. Their relaxation times of the order of 10(-11) s are attributed to the fast reorientation of water molecules and/or fast reorientation of oxonium ions (H3O+). In the lower frequency interval, dielectric relaxations of WPA-6 and some IATA salts with longer relaxation times of the order of 10(-7)-10(-5) s were registered and assigned to ion (H+ and/or H3O+) and cation jumps. (c) 2005 Elsevier B.V. All rights reserved.",
journal = "Solid State Ionics",
title = "The influence of monovalent and bivalent cations on the electrical properties of 12-Tungstophosphoric acid salts",
volume = "176",
number = "39-40",
pages = "2881-2885",
doi = "10.1016/j.ssi.2005.09.020"
}

Davidovic, A., Cajkovski, T., Colomban, P., Mioč, U. B., Likar-Smiljanic, V., Cajkovski, D., Biljic, R.,& Nedić, Z.. (2005). The influence of monovalent and bivalent cations on the electrical properties of 12-Tungstophosphoric acid salts. in Solid State Ionics, 176(39-40), 2881-2885.
https://doi.org/10.1016/j.ssi.2005.09.020

Davidovic A, Cajkovski T, Colomban P, Mioč UB, Likar-Smiljanic V, Cajkovski D, Biljic R, Nedić Z. The influence of monovalent and bivalent cations on the electrical properties of 12-Tungstophosphoric acid salts. in Solid State Ionics. 2005;176(39-40):2881-2885.
doi:10.1016/j.ssi.2005.09.020 .

Davidovic, A, Cajkovski, T, Colomban, P, Mioč, Ubavka B., Likar-Smiljanic, V, Cajkovski, D, Biljic, R, Nedić, Zoran, "The influence of monovalent and bivalent cations on the electrical properties of 12-Tungstophosphoric acid salts" in Solid State Ionics, 176, no. 39-40 (2005):2881-2885,
https://doi.org/10.1016/j.ssi.2005.09.020 . .

TY  - JOUR
AU  - Radić, Martina
AU  - Ignjatović, Nenad L.
AU  - Nedić, Zoran
AU  - Mitrić, Miodrag
AU  - Miličević, Dejan S.
AU  - Uskoković, Dragan
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6541
AB  - In this paper we report the results on synthesis of a composite biomaterial based on biphasic calcium phosphate (BCP) and poly-(DL-lactide-co-glycolide) (DLPLG). Besides, we have investigated the influence of new synthesis method on the structure and characteristics of the composite. The synthesis of biphasic calcium phosphate from Ca(NO3)(2) x 4H(2)O and (NH4)(3) PO4 in alkali environment was performed by means of precipitation technique. Composite material BCP/DLPLG was first prepared from commercial granules using chemical methods. Powdered polymer DLPLG was then homogenized at appropriate ratio with addition of biphasic calcium phosphate into the suspension. All samples were characterized by DSC, IR, X-Ray and SEM techniques.
T2  - Materials Science Forum
T1  - Synthesis and characterization of biphasic calcium phosphate/poly-(DL-lactide-co-glycolide) biocomposite
VL  - 494
SP  - 537
EP  - 542
DO  - 10.4028/www.scientific.net/MSF.494.537
ER  - 

@article{
author = "Radić, Martina and Ignjatović, Nenad L. and Nedić, Zoran and Mitrić, Miodrag and Miličević, Dejan S. and Uskoković, Dragan",
year = "2005",
abstract = "In this paper we report the results on synthesis of a composite biomaterial based on biphasic calcium phosphate (BCP) and poly-(DL-lactide-co-glycolide) (DLPLG). Besides, we have investigated the influence of new synthesis method on the structure and characteristics of the composite. The synthesis of biphasic calcium phosphate from Ca(NO3)(2) x 4H(2)O and (NH4)(3) PO4 in alkali environment was performed by means of precipitation technique. Composite material BCP/DLPLG was first prepared from commercial granules using chemical methods. Powdered polymer DLPLG was then homogenized at appropriate ratio with addition of biphasic calcium phosphate into the suspension. All samples were characterized by DSC, IR, X-Ray and SEM techniques.",
journal = "Materials Science Forum",
title = "Synthesis and characterization of biphasic calcium phosphate/poly-(DL-lactide-co-glycolide) biocomposite",
volume = "494",
pages = "537-542",
doi = "10.4028/www.scientific.net/MSF.494.537"
}

Radić, M., Ignjatović, N. L., Nedić, Z., Mitrić, M., Miličević, D. S.,& Uskoković, D.. (2005). Synthesis and characterization of biphasic calcium phosphate/poly-(DL-lactide-co-glycolide) biocomposite. in Materials Science Forum, 494, 537-542.
https://doi.org/10.4028/www.scientific.net/MSF.494.537

Radić M, Ignjatović NL, Nedić Z, Mitrić M, Miličević DS, Uskoković D. Synthesis and characterization of biphasic calcium phosphate/poly-(DL-lactide-co-glycolide) biocomposite. in Materials Science Forum. 2005;494:537-542.
doi:10.4028/www.scientific.net/MSF.494.537 .

Radić, Martina, Ignjatović, Nenad L., Nedić, Zoran, Mitrić, Miodrag, Miličević, Dejan S., Uskoković, Dragan, "Synthesis and characterization of biphasic calcium phosphate/poly-(DL-lactide-co-glycolide) biocomposite" in Materials Science Forum, 494 (2005):537-542,
https://doi.org/10.4028/www.scientific.net/MSF.494.537 . .

TY  - JOUR
AU  - Sredic, S
AU  - Cajkovski, T
AU  - Davidović, Miloš D.
AU  - Cajkovski, D
AU  - Likar-Smiljanic, V
AU  - Marinović-Cincović, Milena
AU  - Mioč, Ubavka B.
AU  - Nedić, Zoran
AU  - Biljic, R
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6422
AB  - Bentonite a natural raw material from the Sipovo mining deposits (Republic of Srpska), which contains a high percentage of montmorillonite, was treated to obtain montmorillonite clay ready for further investigations. Al-pillared montmorillonite was doped with 12-tungstophosphoric acid (WPA) by the sol-gel method. Substantial increase in proton conductivity of this new material was achieved. Different physicochemical methods were used to characterize new materials such as X-ray powder diffraction (XRD), thermogravimetric (TG) analysis, porosity measurements, scanning electron microscopy (SEM), and infrared measurements (IR). Impedance spectroscopy technique was applied in order to study the proton conductivity and its dependence on the frequency and tungstophosphoric acid concentration.
T2  - Materials Science Forum
T1  - Physicochemical properties of Al-pillared montmorillonite doped with 12-tungstophosphoric acid
VL  - 453-454
SP  - 157
EP  - 162
DO  - 10.4028/www.scientific.net/MSF.453-454.157
ER  - 

@article{
author = "Sredic, S and Cajkovski, T and Davidović, Miloš D. and Cajkovski, D and Likar-Smiljanic, V and Marinović-Cincović, Milena and Mioč, Ubavka B. and Nedić, Zoran and Biljic, R",
year = "2004",
abstract = "Bentonite a natural raw material from the Sipovo mining deposits (Republic of Srpska), which contains a high percentage of montmorillonite, was treated to obtain montmorillonite clay ready for further investigations. Al-pillared montmorillonite was doped with 12-tungstophosphoric acid (WPA) by the sol-gel method. Substantial increase in proton conductivity of this new material was achieved. Different physicochemical methods were used to characterize new materials such as X-ray powder diffraction (XRD), thermogravimetric (TG) analysis, porosity measurements, scanning electron microscopy (SEM), and infrared measurements (IR). Impedance spectroscopy technique was applied in order to study the proton conductivity and its dependence on the frequency and tungstophosphoric acid concentration.",
journal = "Materials Science Forum",
title = "Physicochemical properties of Al-pillared montmorillonite doped with 12-tungstophosphoric acid",
volume = "453-454",
pages = "157-162",
doi = "10.4028/www.scientific.net/MSF.453-454.157"
}

Sredic, S., Cajkovski, T., Davidović, M. D., Cajkovski, D., Likar-Smiljanic, V., Marinović-Cincović, M., Mioč, U. B., Nedić, Z.,& Biljic, R.. (2004). Physicochemical properties of Al-pillared montmorillonite doped with 12-tungstophosphoric acid. in Materials Science Forum, 453-454, 157-162.
https://doi.org/10.4028/www.scientific.net/MSF.453-454.157

Sredic S, Cajkovski T, Davidović MD, Cajkovski D, Likar-Smiljanic V, Marinović-Cincović M, Mioč UB, Nedić Z, Biljic R. Physicochemical properties of Al-pillared montmorillonite doped with 12-tungstophosphoric acid. in Materials Science Forum. 2004;453-454:157-162.
doi:10.4028/www.scientific.net/MSF.453-454.157 .

Sredic, S, Cajkovski, T, Davidović, Miloš D., Cajkovski, D, Likar-Smiljanic, V, Marinović-Cincović, Milena, Mioč, Ubavka B., Nedić, Zoran, Biljic, R, "Physicochemical properties of Al-pillared montmorillonite doped with 12-tungstophosphoric acid" in Materials Science Forum, 453-454 (2004):157-162,
https://doi.org/10.4028/www.scientific.net/MSF.453-454.157 . .

TY  - JOUR
AU  - Nikcevic, I
AU  - Jokanović, Vukoman R.
AU  - Mitrić, Miodrag
AU  - Nedić, Zoran
AU  - Makovec, Darko
AU  - Uskoković, Dragan
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2778
AB  - Powder mixture of Ca(OH)(2)-P2O5-CaF2 were milled in planetary ball mill. A carbonated fluorhydroxyapatite, FHA Ca-10(PO4)(1-y)(CO3)(y)(PO4)(5)(OH)(2-2x1)(F)(2x1) was formed after 5 h of milling and carbonated fluoroapatite Ca-10(PO4)(1-y)(CO3)(y)(PO4)(5)(F)(2) was formed after 9 h of milling. Complete transformation of the carbonated form of FA into then single phase of FA occurred after 9 h milling and thermally treating. The various experimental techniques like X-ray Diffraction (XRD), Differential Thermal Analysis (DTA), Infrared Spectroscopy (IR), Transmission Electron Microscopy and Scanning Electron Microscopy (SEM) were used to characterize the synthesized powders and to postulate reaction mechanisms steps- transformations of reactants involved. (C) 2004 Elsevier Inc. All rights reserved.
T2  - Journal of Solid State Chemistry
T1  - Mechanochemical synthesis of nanostructured fluorapatite/fluorhydroxyapatite and carbonated fluorapatite/fluorhydroxyapatite
VL  - 177
IS  - 7
SP  - 2565
EP  - 2574
DO  - 10.1016/j.jssc.2004.03.024
ER  - 

@article{
author = "Nikcevic, I and Jokanović, Vukoman R. and Mitrić, Miodrag and Nedić, Zoran and Makovec, Darko and Uskoković, Dragan",
year = "2004",
abstract = "Powder mixture of Ca(OH)(2)-P2O5-CaF2 were milled in planetary ball mill. A carbonated fluorhydroxyapatite, FHA Ca-10(PO4)(1-y)(CO3)(y)(PO4)(5)(OH)(2-2x1)(F)(2x1) was formed after 5 h of milling and carbonated fluoroapatite Ca-10(PO4)(1-y)(CO3)(y)(PO4)(5)(F)(2) was formed after 9 h of milling. Complete transformation of the carbonated form of FA into then single phase of FA occurred after 9 h milling and thermally treating. The various experimental techniques like X-ray Diffraction (XRD), Differential Thermal Analysis (DTA), Infrared Spectroscopy (IR), Transmission Electron Microscopy and Scanning Electron Microscopy (SEM) were used to characterize the synthesized powders and to postulate reaction mechanisms steps- transformations of reactants involved. (C) 2004 Elsevier Inc. All rights reserved.",
journal = "Journal of Solid State Chemistry",
title = "Mechanochemical synthesis of nanostructured fluorapatite/fluorhydroxyapatite and carbonated fluorapatite/fluorhydroxyapatite",
volume = "177",
number = "7",
pages = "2565-2574",
doi = "10.1016/j.jssc.2004.03.024"
}

Nikcevic, I., Jokanović, V. R., Mitrić, M., Nedić, Z., Makovec, D.,& Uskoković, D.. (2004). Mechanochemical synthesis of nanostructured fluorapatite/fluorhydroxyapatite and carbonated fluorapatite/fluorhydroxyapatite. in Journal of Solid State Chemistry, 177(7), 2565-2574.
https://doi.org/10.1016/j.jssc.2004.03.024

Nikcevic I, Jokanović VR, Mitrić M, Nedić Z, Makovec D, Uskoković D. Mechanochemical synthesis of nanostructured fluorapatite/fluorhydroxyapatite and carbonated fluorapatite/fluorhydroxyapatite. in Journal of Solid State Chemistry. 2004;177(7):2565-2574.
doi:10.1016/j.jssc.2004.03.024 .

Nikcevic, I, Jokanović, Vukoman R., Mitrić, Miodrag, Nedić, Zoran, Makovec, Darko, Uskoković, Dragan, "Mechanochemical synthesis of nanostructured fluorapatite/fluorhydroxyapatite and carbonated fluorapatite/fluorhydroxyapatite" in Journal of Solid State Chemistry, 177, no. 7 (2004):2565-2574,
https://doi.org/10.1016/j.jssc.2004.03.024 . .

TY  - JOUR
AU  - Cajkovski, T
AU  - Davidović, Miloš D.
AU  - Pissis, P
AU  - Polizos, G
AU  - Cajkovski, D
AU  - Likar-Smiljanic, V
AU  - Biljic, R
AU  - Nedić, Zoran
AU  - Mioč, Ubavka B.
PY  - 2003
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6383
AB  - The electrical and dielectric properties of the copper salt of 12-tungstophosphoric acid (WPA) hydrate have been investigated by broadband dielectric relaxation spectroscopy (DRS). This work is a continuation of our previous investigations on the influence of monovalent and bivalent cations on the dielectric properties of WPA hydrates salts. Measurements were made in the frequency range 10 mHz-1 MHz in order to explore the long-range dynamics, following recent microwave measurements aiming at the local dynamics properties. Experiments were done in the temperature interval 293-350 K. Data treatment included complex permittivity epsilon*, complex electric modulus M* and complex impedance Z* formalism, Arrhenius diagram and Cole-Cole diagrams. The results are discussed in terms of conductivity relaxation and conductivity current relaxation. Rather long conductivity relaxation times measured seem to correspond to ion jumping processes. A phase transition was observed at 323 K. (C) 2003 Elsevier B.V. All rights reserved.
T2  - Solid State Ionics
T1  - Dielectric investigation of electrical conductivity in the copper salt of the 12-tungstophosphoric acid hydrate
VL  - 162
SP  - 203
EP  - 208
DO  - 10.1016/S0167-2738(03)00233-9
ER  - 

@article{
author = "Cajkovski, T and Davidović, Miloš D. and Pissis, P and Polizos, G and Cajkovski, D and Likar-Smiljanic, V and Biljic, R and Nedić, Zoran and Mioč, Ubavka B.",
year = "2003",
abstract = "The electrical and dielectric properties of the copper salt of 12-tungstophosphoric acid (WPA) hydrate have been investigated by broadband dielectric relaxation spectroscopy (DRS). This work is a continuation of our previous investigations on the influence of monovalent and bivalent cations on the dielectric properties of WPA hydrates salts. Measurements were made in the frequency range 10 mHz-1 MHz in order to explore the long-range dynamics, following recent microwave measurements aiming at the local dynamics properties. Experiments were done in the temperature interval 293-350 K. Data treatment included complex permittivity epsilon*, complex electric modulus M* and complex impedance Z* formalism, Arrhenius diagram and Cole-Cole diagrams. The results are discussed in terms of conductivity relaxation and conductivity current relaxation. Rather long conductivity relaxation times measured seem to correspond to ion jumping processes. A phase transition was observed at 323 K. (C) 2003 Elsevier B.V. All rights reserved.",
journal = "Solid State Ionics",
title = "Dielectric investigation of electrical conductivity in the copper salt of the 12-tungstophosphoric acid hydrate",
volume = "162",
pages = "203-208",
doi = "10.1016/S0167-2738(03)00233-9"
}

Cajkovski, T., Davidović, M. D., Pissis, P., Polizos, G., Cajkovski, D., Likar-Smiljanic, V., Biljic, R., Nedić, Z.,& Mioč, U. B.. (2003). Dielectric investigation of electrical conductivity in the copper salt of the 12-tungstophosphoric acid hydrate. in Solid State Ionics, 162, 203-208.
https://doi.org/10.1016/S0167-2738(03)00233-9

Cajkovski T, Davidović MD, Pissis P, Polizos G, Cajkovski D, Likar-Smiljanic V, Biljic R, Nedić Z, Mioč UB. Dielectric investigation of electrical conductivity in the copper salt of the 12-tungstophosphoric acid hydrate. in Solid State Ionics. 2003;162:203-208.
doi:10.1016/S0167-2738(03)00233-9 .

Cajkovski, T, Davidović, Miloš D., Pissis, P, Polizos, G, Cajkovski, D, Likar-Smiljanic, V, Biljic, R, Nedić, Zoran, Mioč, Ubavka B., "Dielectric investigation of electrical conductivity in the copper salt of the 12-tungstophosphoric acid hydrate" in Solid State Ionics, 162 (2003):203-208,
https://doi.org/10.1016/S0167-2738(03)00233-9 . .

TY  - JOUR
AU  - Davidović, Miloš D.
AU  - Cajkovski, T
AU  - Cajkovski, D
AU  - Likar-Smiljanic, V
AU  - Biljic, R
AU  - Mioč, Ubavka B.
AU  - Nedić, Zoran
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2509
AB  - Barium salt of 12-tungstophosphoric acid (WPA) hydrate BaHPW12O40.7H(2)O (BaHWPA-7H20) has been investigated both in the microwave (X-band) region and in the lower frequency (5 Hz-500 kHz) region. This work is a continuation of our previous investigations on the influence of monovalent and bivalent cations on the dielectric properties of WPA hydrate salts. The real and imaginary parts of the permittivity (epsilon, epsilon) as a function of frequency and temperature, were determined in both frequency regions. The observed relaxations were attributed to specific relaxation processes. In the lower frequency range, the relaxation time tau=1.0 x 10(-6) s was assigned to barium ion jumps. In the microwave region, the dielectric relaxation time tau =1.7 x 10(-11) s was attributed to polyatomic ions (H3O+) and/or H2O molecules reorientations. A phase transition was observed at 330 K. The low value of the activation energy for reorientation in the microwave frequency region is discussed. The d.c. conductivity and its temperature dependence were determined. Measurements were made in the temperature interval from 286 to 353 K. In the upper part of this temperature interval a PTCR effect was observed. (C) 2002 Published by Elsevier Science B.V.
T2  - Solid State Ionics
T1  - Dielectric relaxation and conductivity in barium salt of 12-tungstophosphoric acid hydrate
VL  - 147
IS  - 1-2
SP  - 123
EP  - 128
DO  - 10.1016/S0167-2738(02)00003-6
ER  - 

@article{
author = "Davidović, Miloš D. and Cajkovski, T and Cajkovski, D and Likar-Smiljanic, V and Biljic, R and Mioč, Ubavka B. and Nedić, Zoran",
year = "2002",
abstract = "Barium salt of 12-tungstophosphoric acid (WPA) hydrate BaHPW12O40.7H(2)O (BaHWPA-7H20) has been investigated both in the microwave (X-band) region and in the lower frequency (5 Hz-500 kHz) region. This work is a continuation of our previous investigations on the influence of monovalent and bivalent cations on the dielectric properties of WPA hydrate salts. The real and imaginary parts of the permittivity (epsilon, epsilon) as a function of frequency and temperature, were determined in both frequency regions. The observed relaxations were attributed to specific relaxation processes. In the lower frequency range, the relaxation time tau=1.0 x 10(-6) s was assigned to barium ion jumps. In the microwave region, the dielectric relaxation time tau =1.7 x 10(-11) s was attributed to polyatomic ions (H3O+) and/or H2O molecules reorientations. A phase transition was observed at 330 K. The low value of the activation energy for reorientation in the microwave frequency region is discussed. The d.c. conductivity and its temperature dependence were determined. Measurements were made in the temperature interval from 286 to 353 K. In the upper part of this temperature interval a PTCR effect was observed. (C) 2002 Published by Elsevier Science B.V.",
journal = "Solid State Ionics",
title = "Dielectric relaxation and conductivity in barium salt of 12-tungstophosphoric acid hydrate",
volume = "147",
number = "1-2",
pages = "123-128",
doi = "10.1016/S0167-2738(02)00003-6"
}

Davidović, M. D., Cajkovski, T., Cajkovski, D., Likar-Smiljanic, V., Biljic, R., Mioč, U. B.,& Nedić, Z.. (2002). Dielectric relaxation and conductivity in barium salt of 12-tungstophosphoric acid hydrate. in Solid State Ionics, 147(1-2), 123-128.
https://doi.org/10.1016/S0167-2738(02)00003-6

Davidović MD, Cajkovski T, Cajkovski D, Likar-Smiljanic V, Biljic R, Mioč UB, Nedić Z. Dielectric relaxation and conductivity in barium salt of 12-tungstophosphoric acid hydrate. in Solid State Ionics. 2002;147(1-2):123-128.
doi:10.1016/S0167-2738(02)00003-6 .

Davidović, Miloš D., Cajkovski, T, Cajkovski, D, Likar-Smiljanic, V, Biljic, R, Mioč, Ubavka B., Nedić, Zoran, "Dielectric relaxation and conductivity in barium salt of 12-tungstophosphoric acid hydrate" in Solid State Ionics, 147, no. 1-2 (2002):123-128,
https://doi.org/10.1016/S0167-2738(02)00003-6 . .

TY  - JOUR
AU  - Cajkovski, T
AU  - Davidović, Milorad P.
AU  - Cajkovski, D
AU  - Likar-Smiljanic, V
AU  - Biljic, R
AU  - Mioč, Ubavka B.
AU  - Nedić, Zoran
PY  - 2000
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6312
AB  - Complex permittivity of 12-tungstophosphoric acid hexahydrate (H3PW12O40 6H(2)O), 6-WPA has been measured at microwave frequencies (X-band) in the temperature interval from 296 K to 350 K. From 296 K to 328 K 6-WPA displays dipolar relaxation of the Debye type at the frequency f(1)=9.30 GHz which corresponds to the relaxation time tau (1)=1.7x10(11) s. From 328 K to 350 K large changes of epsilon (f) and epsilon (f) take place. Two additional relaxations appear at frequencies f(2)=8.25 GHz and f(3)=10.80 GHz. These additional relaxations could be due to protonic entities that become excited at higher temperatures. An assignation of these relaxations to specific proton entities is proposed.
T2  - Materials Science Forum
T1  - Temperature dependence of dielectric relaxation in 12-tungstophosphoric acid hexahydrate at microwave frequencies
VL  - 352
SP  - 251
EP  - 254
UR  - https://hdl.handle.net/21.15107/rcub_vinar_6312
ER  - 

@article{
author = "Cajkovski, T and Davidović, Milorad P. and Cajkovski, D and Likar-Smiljanic, V and Biljic, R and Mioč, Ubavka B. and Nedić, Zoran",
year = "2000",
abstract = "Complex permittivity of 12-tungstophosphoric acid hexahydrate (H3PW12O40 6H(2)O), 6-WPA has been measured at microwave frequencies (X-band) in the temperature interval from 296 K to 350 K. From 296 K to 328 K 6-WPA displays dipolar relaxation of the Debye type at the frequency f(1)=9.30 GHz which corresponds to the relaxation time tau (1)=1.7x10(11) s. From 328 K to 350 K large changes of epsilon (f) and epsilon (f) take place. Two additional relaxations appear at frequencies f(2)=8.25 GHz and f(3)=10.80 GHz. These additional relaxations could be due to protonic entities that become excited at higher temperatures. An assignation of these relaxations to specific proton entities is proposed.",
journal = "Materials Science Forum",
title = "Temperature dependence of dielectric relaxation in 12-tungstophosphoric acid hexahydrate at microwave frequencies",
volume = "352",
pages = "251-254",
url = "https://hdl.handle.net/21.15107/rcub_vinar_6312"
}

Cajkovski, T., Davidović, M. P., Cajkovski, D., Likar-Smiljanic, V., Biljic, R., Mioč, U. B.,& Nedić, Z.. (2000). Temperature dependence of dielectric relaxation in 12-tungstophosphoric acid hexahydrate at microwave frequencies. in Materials Science Forum, 352, 251-254.
https://hdl.handle.net/21.15107/rcub_vinar_6312

Cajkovski T, Davidović MP, Cajkovski D, Likar-Smiljanic V, Biljic R, Mioč UB, Nedić Z. Temperature dependence of dielectric relaxation in 12-tungstophosphoric acid hexahydrate at microwave frequencies. in Materials Science Forum. 2000;352:251-254.
https://hdl.handle.net/21.15107/rcub_vinar_6312 .

Cajkovski, T, Davidović, Milorad P., Cajkovski, D, Likar-Smiljanic, V, Biljic, R, Mioč, Ubavka B., Nedić, Zoran, "Temperature dependence of dielectric relaxation in 12-tungstophosphoric acid hexahydrate at microwave frequencies" in Materials Science Forum, 352 (2000):251-254,
https://hdl.handle.net/21.15107/rcub_vinar_6312 .

TY  - JOUR
AU  - Mioč, Ubavka B.
AU  - Todorović, M
AU  - Uskoković-Marković, S
AU  - Nedić, Zoran
AU  - Stamenkovic, V
AU  - Cajkovski, T
PY  - 2000
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6292
AB  - In this paper local processes and structural phase transformations of the copper salt of 12-tungstophosphoric acid are investigated. The structural phase transformations were followed through bands, characteristic for the host lattice, in the IR and Raman spectra. The results of these investigations, as well as those of XRPD analysis and impedance measurements as a function of temperature show that some local processes provoke the change in the secondary structure of the Keggin anions.
T2  - Journal of the Serbian Chemical Society
T1  - Structural modifications of Cu(II) 12-tungstophosphoric acid salit studied by IR and Raman spectroscopy
VL  - 65
IS  - 5-6
SP  - 407
EP  - 415
UR  - https://hdl.handle.net/21.15107/rcub_vinar_6292
ER  - 

@article{
author = "Mioč, Ubavka B. and Todorović, M and Uskoković-Marković, S and Nedić, Zoran and Stamenkovic, V and Cajkovski, T",
year = "2000",
abstract = "In this paper local processes and structural phase transformations of the copper salt of 12-tungstophosphoric acid are investigated. The structural phase transformations were followed through bands, characteristic for the host lattice, in the IR and Raman spectra. The results of these investigations, as well as those of XRPD analysis and impedance measurements as a function of temperature show that some local processes provoke the change in the secondary structure of the Keggin anions.",
journal = "Journal of the Serbian Chemical Society",
title = "Structural modifications of Cu(II) 12-tungstophosphoric acid salit studied by IR and Raman spectroscopy",
volume = "65",
number = "5-6",
pages = "407-415",
url = "https://hdl.handle.net/21.15107/rcub_vinar_6292"
}

Mioč, U. B., Todorović, M., Uskoković-Marković, S., Nedić, Z., Stamenkovic, V.,& Cajkovski, T.. (2000). Structural modifications of Cu(II) 12-tungstophosphoric acid salit studied by IR and Raman spectroscopy. in Journal of the Serbian Chemical Society, 65(5-6), 407-415.
https://hdl.handle.net/21.15107/rcub_vinar_6292

Mioč UB, Todorović M, Uskoković-Marković S, Nedić Z, Stamenkovic V, Cajkovski T. Structural modifications of Cu(II) 12-tungstophosphoric acid salit studied by IR and Raman spectroscopy. in Journal of the Serbian Chemical Society. 2000;65(5-6):407-415.
https://hdl.handle.net/21.15107/rcub_vinar_6292 .

Mioč, Ubavka B., Todorović, M, Uskoković-Marković, S, Nedić, Zoran, Stamenkovic, V, Cajkovski, T, "Structural modifications of Cu(II) 12-tungstophosphoric acid salit studied by IR and Raman spectroscopy" in Journal of the Serbian Chemical Society, 65, no. 5-6 (2000):407-415,
https://hdl.handle.net/21.15107/rcub_vinar_6292 .

TY  - JOUR
AU  - Davidović, Miloš D.
AU  - Cajkovski, T
AU  - Cajkovski, D
AU  - Likar-Smiljanic, V
AU  - Biljic, R
AU  - Mioč, Ubavka B.
AU  - Nedić, Zoran
PY  - 1999
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6283
AB  - Magnesium salt of 12-tungstophosphoric acid (WPA) hydrate MgHPW12O40-14H(2)O has been investigated in the microwave (X-band) and in the lower frequency (5 Hz-500 kHz) region. The specimens were obtained by pressing powder. Real and imaginary parts of permittivity were obtained for the specimens in both frequency regions. In the microwave region dipolar relaxation was observed with the relaxation time tau = 1.6 X 10(-11) s. This relaxation is attributed to the fast reorientation of H2O molecules. In the lower frequency region ionic jump relaxation was observed with the relaxation time tau = 3.9 X 10(-7) s. Results on ac and dc conductivity are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.
T2  - Solid State Ionics
T1  - Dielectric investigation of magnesium salt of 12-tungstophosphoric acid hydrate
VL  - 125
IS  - 1-4
SP  - 411
EP  - 415
DO  - 10.1016/S0167-2738(99)00203-9
ER  - 

@article{
author = "Davidović, Miloš D. and Cajkovski, T and Cajkovski, D and Likar-Smiljanic, V and Biljic, R and Mioč, Ubavka B. and Nedić, Zoran",
year = "1999",
abstract = "Magnesium salt of 12-tungstophosphoric acid (WPA) hydrate MgHPW12O40-14H(2)O has been investigated in the microwave (X-band) and in the lower frequency (5 Hz-500 kHz) region. The specimens were obtained by pressing powder. Real and imaginary parts of permittivity were obtained for the specimens in both frequency regions. In the microwave region dipolar relaxation was observed with the relaxation time tau = 1.6 X 10(-11) s. This relaxation is attributed to the fast reorientation of H2O molecules. In the lower frequency region ionic jump relaxation was observed with the relaxation time tau = 3.9 X 10(-7) s. Results on ac and dc conductivity are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.",
journal = "Solid State Ionics",
title = "Dielectric investigation of magnesium salt of 12-tungstophosphoric acid hydrate",
volume = "125",
number = "1-4",
pages = "411-415",
doi = "10.1016/S0167-2738(99)00203-9"
}

Davidović, M. D., Cajkovski, T., Cajkovski, D., Likar-Smiljanic, V., Biljic, R., Mioč, U. B.,& Nedić, Z.. (1999). Dielectric investigation of magnesium salt of 12-tungstophosphoric acid hydrate. in Solid State Ionics, 125(1-4), 411-415.
https://doi.org/10.1016/S0167-2738(99)00203-9

Davidović MD, Cajkovski T, Cajkovski D, Likar-Smiljanic V, Biljic R, Mioč UB, Nedić Z. Dielectric investigation of magnesium salt of 12-tungstophosphoric acid hydrate. in Solid State Ionics. 1999;125(1-4):411-415.
doi:10.1016/S0167-2738(99)00203-9 .

Davidović, Miloš D., Cajkovski, T, Cajkovski, D, Likar-Smiljanic, V, Biljic, R, Mioč, Ubavka B., Nedić, Zoran, "Dielectric investigation of magnesium salt of 12-tungstophosphoric acid hydrate" in Solid State Ionics, 125, no. 1-4 (1999):411-415,
https://doi.org/10.1016/S0167-2738(99)00203-9 . .

TY  - JOUR
AU  - Cajkovski, T
AU  - Davidović, Milorad P.
AU  - Cajkovski, D
AU  - Likar-Smiljanic, V
AU  - Biljic, R
AU  - Mioč, Ubavka B.
AU  - Nedić, Zoran
PY  - 1998
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6251
AB  - Complex permittivity measurements have been performed on lithium and cesium salts of 12-tungstophosphoric acid hydrates (H3PW12O40.nH(2)O) within the frequency region of the microwave X-band (8 - 12 GHz) and at room temperature. Dielectric relaxation spectra have been observed for both salts. For the lithium salt (Li3PW12O40.11H(2)O) one dipolar relaxation has been recorded, whereas for the cesium salt (CS3PW12O40.10H(2)O) two dipolar relaxations have been registered. The results are discussed by assuming that the fast reorientation of H2O molecules and oxonium ions (H3O+) contribute to the observed relaxations. Dynamical conductivity results exhibit frequency dependence with a waviness reflecting the observed dipolar relaxations.
T2  - Materials Science Forum
T1  - X-band microwave permittivity measurements on lithium and cesium salts of 12-tunstophosphoric acid
VL  - 282-2
SP  - 193
EP  - 197
UR  - https://hdl.handle.net/21.15107/rcub_vinar_6251
ER  - 

@article{
author = "Cajkovski, T and Davidović, Milorad P. and Cajkovski, D and Likar-Smiljanic, V and Biljic, R and Mioč, Ubavka B. and Nedić, Zoran",
year = "1998",
abstract = "Complex permittivity measurements have been performed on lithium and cesium salts of 12-tungstophosphoric acid hydrates (H3PW12O40.nH(2)O) within the frequency region of the microwave X-band (8 - 12 GHz) and at room temperature. Dielectric relaxation spectra have been observed for both salts. For the lithium salt (Li3PW12O40.11H(2)O) one dipolar relaxation has been recorded, whereas for the cesium salt (CS3PW12O40.10H(2)O) two dipolar relaxations have been registered. The results are discussed by assuming that the fast reorientation of H2O molecules and oxonium ions (H3O+) contribute to the observed relaxations. Dynamical conductivity results exhibit frequency dependence with a waviness reflecting the observed dipolar relaxations.",
journal = "Materials Science Forum",
title = "X-band microwave permittivity measurements on lithium and cesium salts of 12-tunstophosphoric acid",
volume = "282-2",
pages = "193-197",
url = "https://hdl.handle.net/21.15107/rcub_vinar_6251"
}

Cajkovski, T., Davidović, M. P., Cajkovski, D., Likar-Smiljanic, V., Biljic, R., Mioč, U. B.,& Nedić, Z.. (1998). X-band microwave permittivity measurements on lithium and cesium salts of 12-tunstophosphoric acid. in Materials Science Forum, 282-2, 193-197.
https://hdl.handle.net/21.15107/rcub_vinar_6251

Cajkovski T, Davidović MP, Cajkovski D, Likar-Smiljanic V, Biljic R, Mioč UB, Nedić Z. X-band microwave permittivity measurements on lithium and cesium salts of 12-tunstophosphoric acid. in Materials Science Forum. 1998;282-2:193-197.
https://hdl.handle.net/21.15107/rcub_vinar_6251 .

Cajkovski, T, Davidović, Milorad P., Cajkovski, D, Likar-Smiljanic, V, Biljic, R, Mioč, Ubavka B., Nedić, Zoran, "X-band microwave permittivity measurements on lithium and cesium salts of 12-tunstophosphoric acid" in Materials Science Forum, 282-2 (1998):193-197,
https://hdl.handle.net/21.15107/rcub_vinar_6251 .