TY  - JOUR
AU  - Ćosović, Vladan
AU  - Talijan, Nadežda M.
AU  - Grujić, Aleksandar
AU  - Stajić-Trošić, Jasna
AU  - Žak, Tomas
AU  - Lee, Z.
AU  - Radmilović, V.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/514
AB  - Characterization of two rapid-quenched Nd-Fe-B alloys with nonstoichiometric Nd content in the optimized magnetic state was carried out using the X-ray diffractometry (XRD), 57Fe Mössbauer spectroscopic phase analysis (MS), electron microscopy (TEM), high resolution TEM (HREM) and Superconducting Quantum Interference Device (SQUID) magnetometer. The experimental results demonstrate the fundamental difference in the structure and magnetic properties of the two investigated alloys in the optimized magnetic state. The Nd-Fe-B alloy with the reduced Nd content (Nd4.5Fe77B18.5) was found to have the nanocomposite structure of Fe3B/Nd2Fe14B and partly α-Fe/Nd2Fe14B, with mean grain size below 30 nm. On the other side, the overstoichiometric Nd14Fe79B7 alloy has almost a monophase structure with the dominant content of the hard magnetic phase Nd2Fe14B (up to 95 wt. %) and a mean crystallite size about 60 nm, as determined by XRD and TEM analysis. The results of magnetic measurements on SQUID magnetometer also suggest the nanocomposite structure of the Nd-low alloy and nanocrystalline decoupled structure of the Nd-rich alloy after the optimal heat treatment.
AB  - Dva tipa brzo hlađenih Nd-Fe-B legura sa nestehiometrijskim sadržajem neodijuma analizirani su u optimalnom magnetnom stanju primenom rendgensko- difraktometrijske analize (XRD), 57Fe Mössbauer spektroskopske fazne analize (MS), transmisione elektronske mikroskopije (TEM) i transmisione elektronske mikroskopije visoke rezolucije (HREM). Magnetna merenja vršena su na SQUID magnetometru. Dobijeni eksperimentalni rezultati ukazuju na fundamentalnu razliku u strukturi i magnetnim svojstvima ispitivanih legura u optimalnom magnetnom stanju. Eksperimentalno je pokazano da Nd4.5Fe77B18.5 - legura sa redukovanim sadržajem Nd, ima nanokompozitnu strukturu tipa Fe3B/Nd2Fe14B sa delimičnim učešćem α-Fe faze i srednju veličinu kristalnih zrna prisutnih faza ispod 30 nm. Sa druge strane, Nd14Fe79B7 - legura obogaćena na Nd, ima pretežno monofaznu strukturu sa dominantnim sadržajem tvrde magnetne faze Nd2Fe14B (do 95 mas. %) i srednju veličinu zrna oko 60 nm, utvrđenu XRD i TEM analizom. Rezultati magnetnih merenja na SQUID magnetometru takođe ukazuju na nanokompozitnu strukturu Nd-Fe-B legure sa redukovanim sadržajem Nd odnosno na nanokristalnu dekuplovanu strukturu legure obogaćene na neodijumu, posle optimalnog termičkog tretmana.
PB  - International Institute for the Science of Sintering, Beograd
T2  - Science of Sintering
T1  - Study of Nd-Fe-B alloys with nonstoichiometric Nd content in optimal magnetic state
VL  - 41
IS  - 2
SP  - 211
EP  - 220
DO  - 10.2298/SOS0902209C
ER  - 

@article{
author = "Ćosović, Vladan and Talijan, Nadežda M. and Grujić, Aleksandar and Stajić-Trošić, Jasna and Žak, Tomas and Lee, Z. and Radmilović, V.",
year = "2009",
abstract = "Characterization of two rapid-quenched Nd-Fe-B alloys with nonstoichiometric Nd content in the optimized magnetic state was carried out using the X-ray diffractometry (XRD), 57Fe Mössbauer spectroscopic phase analysis (MS), electron microscopy (TEM), high resolution TEM (HREM) and Superconducting Quantum Interference Device (SQUID) magnetometer. The experimental results demonstrate the fundamental difference in the structure and magnetic properties of the two investigated alloys in the optimized magnetic state. The Nd-Fe-B alloy with the reduced Nd content (Nd4.5Fe77B18.5) was found to have the nanocomposite structure of Fe3B/Nd2Fe14B and partly α-Fe/Nd2Fe14B, with mean grain size below 30 nm. On the other side, the overstoichiometric Nd14Fe79B7 alloy has almost a monophase structure with the dominant content of the hard magnetic phase Nd2Fe14B (up to 95 wt. %) and a mean crystallite size about 60 nm, as determined by XRD and TEM analysis. The results of magnetic measurements on SQUID magnetometer also suggest the nanocomposite structure of the Nd-low alloy and nanocrystalline decoupled structure of the Nd-rich alloy after the optimal heat treatment., Dva tipa brzo hlađenih Nd-Fe-B legura sa nestehiometrijskim sadržajem neodijuma analizirani su u optimalnom magnetnom stanju primenom rendgensko- difraktometrijske analize (XRD), 57Fe Mössbauer spektroskopske fazne analize (MS), transmisione elektronske mikroskopije (TEM) i transmisione elektronske mikroskopije visoke rezolucije (HREM). Magnetna merenja vršena su na SQUID magnetometru. Dobijeni eksperimentalni rezultati ukazuju na fundamentalnu razliku u strukturi i magnetnim svojstvima ispitivanih legura u optimalnom magnetnom stanju. Eksperimentalno je pokazano da Nd4.5Fe77B18.5 - legura sa redukovanim sadržajem Nd, ima nanokompozitnu strukturu tipa Fe3B/Nd2Fe14B sa delimičnim učešćem α-Fe faze i srednju veličinu kristalnih zrna prisutnih faza ispod 30 nm. Sa druge strane, Nd14Fe79B7 - legura obogaćena na Nd, ima pretežno monofaznu strukturu sa dominantnim sadržajem tvrde magnetne faze Nd2Fe14B (do 95 mas. %) i srednju veličinu zrna oko 60 nm, utvrđenu XRD i TEM analizom. Rezultati magnetnih merenja na SQUID magnetometru takođe ukazuju na nanokompozitnu strukturu Nd-Fe-B legure sa redukovanim sadržajem Nd odnosno na nanokristalnu dekuplovanu strukturu legure obogaćene na neodijumu, posle optimalnog termičkog tretmana.",
publisher = "International Institute for the Science of Sintering, Beograd",
journal = "Science of Sintering",
title = "Study of Nd-Fe-B alloys with nonstoichiometric Nd content in optimal magnetic state",
volume = "41",
number = "2",
pages = "211-220",
doi = "10.2298/SOS0902209C"
}

Ćosović, V., Talijan, N. M., Grujić, A., Stajić-Trošić, J., Žak, T., Lee, Z.,& Radmilović, V.. (2009). Study of Nd-Fe-B alloys with nonstoichiometric Nd content in optimal magnetic state. in Science of Sintering
International Institute for the Science of Sintering, Beograd., 41(2), 211-220.
https://doi.org/10.2298/SOS0902209C

Ćosović V, Talijan NM, Grujić A, Stajić-Trošić J, Žak T, Lee Z, Radmilović V. Study of Nd-Fe-B alloys with nonstoichiometric Nd content in optimal magnetic state. in Science of Sintering. 2009;41(2):211-220.
doi:10.2298/SOS0902209C .

Ćosović, Vladan, Talijan, Nadežda M., Grujić, Aleksandar, Stajić-Trošić, Jasna, Žak, Tomas, Lee, Z., Radmilović, V., "Study of Nd-Fe-B alloys with nonstoichiometric Nd content in optimal magnetic state" in Science of Sintering, 41, no. 2 (2009):211-220,
https://doi.org/10.2298/SOS0902209C . .

TY  - JOUR
AU  - Tripković, Amalija
AU  - Popović, Ksenija
AU  - Lović, Jelena
AU  - Marković, Nenad M.
AU  - Radmilović, V.
PY  - 2005
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/213
AB  - The formic acid oxidation on Pt/Ru nanoparticles in acid solution over the temperature range 298-333 K has been studied by thin-film rotating disk method (RDE). Transmission electron microscopy in combination with scanning tunneling microscopy was used to determine the size (4.3 +/- 0.3 nm) and shape (cuboctahedral) of the particles. Kinetic analysis revealed that at elevated temperatures (313 K, 333 K) the reaction rate is much higher than at room temperature (295 K), indicating that formic acid oxidation on supported Pt/Ru catalyst is a highly activated process. Based on experimental kinetic parameters we propose that the HCOOH oxidation on the PtRu alloy most likely follows a dual pathway, but the branching ratio is still very high, i.e. Pt-like. The principal effect of opening the dehydration channel at steady-state (via the presence of Ru in the surface) is to lower the coverage of COads on Pt sites and permit the dehydrogenation path to increase in rate.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
T2  - Current Research in Advanced Materials and Processes
T1  - Formic acid oxidation on Pt/Ru nanoparticles: Temperature effects
VL  - 494
SP  - 223
EP  - 228
DO  - 10.4028/www.scientific.net/MSF.494.223
ER  - 

@article{
author = "Tripković, Amalija and Popović, Ksenija and Lović, Jelena and Marković, Nenad M. and Radmilović, V.",
year = "2005",
abstract = "The formic acid oxidation on Pt/Ru nanoparticles in acid solution over the temperature range 298-333 K has been studied by thin-film rotating disk method (RDE). Transmission electron microscopy in combination with scanning tunneling microscopy was used to determine the size (4.3 +/- 0.3 nm) and shape (cuboctahedral) of the particles. Kinetic analysis revealed that at elevated temperatures (313 K, 333 K) the reaction rate is much higher than at room temperature (295 K), indicating that formic acid oxidation on supported Pt/Ru catalyst is a highly activated process. Based on experimental kinetic parameters we propose that the HCOOH oxidation on the PtRu alloy most likely follows a dual pathway, but the branching ratio is still very high, i.e. Pt-like. The principal effect of opening the dehydration channel at steady-state (via the presence of Ru in the surface) is to lower the coverage of COads on Pt sites and permit the dehydrogenation path to increase in rate.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Current Research in Advanced Materials and Processes",
title = "Formic acid oxidation on Pt/Ru nanoparticles: Temperature effects",
volume = "494",
pages = "223-228",
doi = "10.4028/www.scientific.net/MSF.494.223"
}

Tripković, A., Popović, K., Lović, J., Marković, N. M.,& Radmilović, V.. (2005). Formic acid oxidation on Pt/Ru nanoparticles: Temperature effects. in Current Research in Advanced Materials and Processes
Trans Tech Publications Ltd, Durnten-Zurich., 494, 223-228.
https://doi.org/10.4028/www.scientific.net/MSF.494.223

Tripković A, Popović K, Lović J, Marković NM, Radmilović V. Formic acid oxidation on Pt/Ru nanoparticles: Temperature effects. in Current Research in Advanced Materials and Processes. 2005;494:223-228.
doi:10.4028/www.scientific.net/MSF.494.223 .

Tripković, Amalija, Popović, Ksenija, Lović, Jelena, Marković, Nenad M., Radmilović, V., "Formic acid oxidation on Pt/Ru nanoparticles: Temperature effects" in Current Research in Advanced Materials and Processes, 494 (2005):223-228,
https://doi.org/10.4028/www.scientific.net/MSF.494.223 . .