TY  - JOUR
AU  - Cvetković, Vesna S.
AU  - Feldhaus, Dominic
AU  - Vukićević, Nataša M.
AU  - Milićević-Neumann, Ksenija
AU  - Barudžija, Tanja
AU  - Friedrich, Bernd
AU  - Jovićević, Jovan N.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10416
AB  - The impact of rare earth oxide (REO) concentration on the deposition process and selective recovery of the metal being deposited from a molten fluoride salt system was investigated by applying deposition of Nd and Pr and varying the concentration of REO added to the electrolyte. A ternary phase diagram for the liquidus temperature of the NdF3-PrF3-LiF system was constructed to better predict the optimal electrolyte constitution. Cyclic voltammetry was used to record three redox signals, reflecting the processes involving Nd(III)/Nd and Pr(III)/Pr transformations. A two-step red/ox process for Nd(III) ions and a single-step red/ox process for Pr(III) ions were confirmed by square-wave voltammetry. The cyclic voltammetry results indicated the possibility of neodymium and praseodymium co-deposition. In order to sustain higher co-deposition rates on the cathode and to avoid increased production of PFC greenhouse gases on the anode, a low-overpotential deposition technique was used for Nd and Pr electrodeposition from the electrolyte with varying Nd2O3 and Pr6O11 concentrations. Co-deposited neodymium and praseodymium metals were characterized by electron probe microanalysis (EPMA) and X-ray diffraction (XRD) analysis. After electrodeposition, concentration profiles of neodymium and praseodymium were recorded, starting from the cathode surface towards the electrolyte bulk. The working temperature of 1050 °C of the molten fluoride salt basic electrolyte, in line with the constructed phase diagram, was validated by improved co-deposition and led to a more effective deposition process.
T2  - Metals
T1  - Influence of Rare Earth Oxide Concentration on Electrochemical
Co-Deposition of Nd and Pr from NdF3-PrF3-LiF Based Melts
VL  - 12
IS  - 7
SP  - 1204
DO  - 10.3390/met12071204
ER  - 

@article{
author = "Cvetković, Vesna S. and Feldhaus, Dominic and Vukićević, Nataša M. and Milićević-Neumann, Ksenija and Barudžija, Tanja and Friedrich, Bernd and Jovićević, Jovan N.",
year = "2022",
abstract = "The impact of rare earth oxide (REO) concentration on the deposition process and selective recovery of the metal being deposited from a molten fluoride salt system was investigated by applying deposition of Nd and Pr and varying the concentration of REO added to the electrolyte. A ternary phase diagram for the liquidus temperature of the NdF3-PrF3-LiF system was constructed to better predict the optimal electrolyte constitution. Cyclic voltammetry was used to record three redox signals, reflecting the processes involving Nd(III)/Nd and Pr(III)/Pr transformations. A two-step red/ox process for Nd(III) ions and a single-step red/ox process for Pr(III) ions were confirmed by square-wave voltammetry. The cyclic voltammetry results indicated the possibility of neodymium and praseodymium co-deposition. In order to sustain higher co-deposition rates on the cathode and to avoid increased production of PFC greenhouse gases on the anode, a low-overpotential deposition technique was used for Nd and Pr electrodeposition from the electrolyte with varying Nd2O3 and Pr6O11 concentrations. Co-deposited neodymium and praseodymium metals were characterized by electron probe microanalysis (EPMA) and X-ray diffraction (XRD) analysis. After electrodeposition, concentration profiles of neodymium and praseodymium were recorded, starting from the cathode surface towards the electrolyte bulk. The working temperature of 1050 °C of the molten fluoride salt basic electrolyte, in line with the constructed phase diagram, was validated by improved co-deposition and led to a more effective deposition process.",
journal = "Metals",
title = "Influence of Rare Earth Oxide Concentration on Electrochemical
Co-Deposition of Nd and Pr from NdF3-PrF3-LiF Based Melts",
volume = "12",
number = "7",
pages = "1204",
doi = "10.3390/met12071204"
}

Cvetković, V. S., Feldhaus, D., Vukićević, N. M., Milićević-Neumann, K., Barudžija, T., Friedrich, B.,& Jovićević, J. N.. (2022). Influence of Rare Earth Oxide Concentration on Electrochemical
Co-Deposition of Nd and Pr from NdF3-PrF3-LiF Based Melts. in Metals, 12(7), 1204.
https://doi.org/10.3390/met12071204

Cvetković VS, Feldhaus D, Vukićević NM, Milićević-Neumann K, Barudžija T, Friedrich B, Jovićević JN. Influence of Rare Earth Oxide Concentration on Electrochemical
Co-Deposition of Nd and Pr from NdF3-PrF3-LiF Based Melts. in Metals. 2022;12(7):1204.
doi:10.3390/met12071204 .

Cvetković, Vesna S., Feldhaus, Dominic, Vukićević, Nataša M., Milićević-Neumann, Ksenija, Barudžija, Tanja, Friedrich, Bernd, Jovićević, Jovan N., "Influence of Rare Earth Oxide Concentration on Electrochemical
Co-Deposition of Nd and Pr from NdF3-PrF3-LiF Based Melts" in Metals, 12, no. 7 (2022):1204,
https://doi.org/10.3390/met12071204 . .

TY  - JOUR
AU  - Cvetković, Vesna S.
AU  - Feldhaus, Dominic
AU  - Vukićević, Nataša M.
AU  - Barudžija, Tanja
AU  - Friedrich, Bernd
AU  - Jovićević, Jovan N.
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9947
AB  - Electrodeposition processes of neodymium and praseodymium in molten NdF3 + PrF3 + LiF + 1 wt.%Pr6O11 + 1 wt.%Nd2O3 and NdF3 + PrF3 + LiF + 2 wt.%Pr6O11 + 2 wt.%Nd2O3 electrolytes at 1323 K were investigated. Cyclic voltammetry, square wave voltammetry, and open circuit potentiometry were applied to study the electrochemical reduction of Nd(III) and Pr(III) ions on Mo and W cathodes. It was established that a critical condition for Nd and Pr co-deposition in oxyfluoride electrolytes was a constant praseodymium deposition overpotential of ≈−0.100 V, which was shown to result in co-deposition current densities approaching 6 mAcm−2 . Analysis of the results obtained by applied electrochemical techniques showed that praseodymium deposition proceeds as a one-step process involving exchange of three electrons (Pr(III)→Pr(0)) and that neodymium deposition is a two-step process: the first involves one electron exchange (Nd(III)→Nd(II)), and the second involves an exchange of two electrons (Nd(II)→Nd(0)). X-ray diffraction analyses confirmed the formation of metallic Nd and Pr on the working substrate. Keeping the anodic potential to the glassy carbon working anode low results in very low levels of carbon oxides, fluorine and fluorocarbon gas emissions, which should qualify the studied system as an environmentally friendly option for rare earth metal deposition. The newly reported data for Nd and Pr metals co-deposition provide valuable information for the recycling of neodymium-iron-boron magnets.
T2  - Metals
T1  - Electrochemical study of Nd and Pr co-deposition onto Mo and W from molten oxyfluorides
VL  - 11
IS  - 9
SP  - 1494
DO  - 10.3390/met11091494
ER  - 

@article{
author = "Cvetković, Vesna S. and Feldhaus, Dominic and Vukićević, Nataša M. and Barudžija, Tanja and Friedrich, Bernd and Jovićević, Jovan N.",
year = "2021",
abstract = "Electrodeposition processes of neodymium and praseodymium in molten NdF3 + PrF3 + LiF + 1 wt.%Pr6O11 + 1 wt.%Nd2O3 and NdF3 + PrF3 + LiF + 2 wt.%Pr6O11 + 2 wt.%Nd2O3 electrolytes at 1323 K were investigated. Cyclic voltammetry, square wave voltammetry, and open circuit potentiometry were applied to study the electrochemical reduction of Nd(III) and Pr(III) ions on Mo and W cathodes. It was established that a critical condition for Nd and Pr co-deposition in oxyfluoride electrolytes was a constant praseodymium deposition overpotential of ≈−0.100 V, which was shown to result in co-deposition current densities approaching 6 mAcm−2 . Analysis of the results obtained by applied electrochemical techniques showed that praseodymium deposition proceeds as a one-step process involving exchange of three electrons (Pr(III)→Pr(0)) and that neodymium deposition is a two-step process: the first involves one electron exchange (Nd(III)→Nd(II)), and the second involves an exchange of two electrons (Nd(II)→Nd(0)). X-ray diffraction analyses confirmed the formation of metallic Nd and Pr on the working substrate. Keeping the anodic potential to the glassy carbon working anode low results in very low levels of carbon oxides, fluorine and fluorocarbon gas emissions, which should qualify the studied system as an environmentally friendly option for rare earth metal deposition. The newly reported data for Nd and Pr metals co-deposition provide valuable information for the recycling of neodymium-iron-boron magnets.",
journal = "Metals",
title = "Electrochemical study of Nd and Pr co-deposition onto Mo and W from molten oxyfluorides",
volume = "11",
number = "9",
pages = "1494",
doi = "10.3390/met11091494"
}

Cvetković, V. S., Feldhaus, D., Vukićević, N. M., Barudžija, T., Friedrich, B.,& Jovićević, J. N.. (2021). Electrochemical study of Nd and Pr co-deposition onto Mo and W from molten oxyfluorides. in Metals, 11(9), 1494.
https://doi.org/10.3390/met11091494

Cvetković VS, Feldhaus D, Vukićević NM, Barudžija T, Friedrich B, Jovićević JN. Electrochemical study of Nd and Pr co-deposition onto Mo and W from molten oxyfluorides. in Metals. 2021;11(9):1494.
doi:10.3390/met11091494 .

Cvetković, Vesna S., Feldhaus, Dominic, Vukićević, Nataša M., Barudžija, Tanja, Friedrich, Bernd, Jovićević, Jovan N., "Electrochemical study of Nd and Pr co-deposition onto Mo and W from molten oxyfluorides" in Metals, 11, no. 9 (2021):1494,
https://doi.org/10.3390/met11091494 . .

TY  - JOUR
AU  - Cvetković, Vesna S.
AU  - Vukićević, Nataša
AU  - Feldhaus, Dominic
AU  - Barudžija, Tanja
AU  - Stevanović, Jasmina
AU  - Friedrich, Bernd
AU  - Jovićević, Jovan J.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9073
AB  - Electrochemical reduction processes of Nd(III) on tungsten and molybdenum electrodes in NdF3+LiF and NdF3+LiF+Nd2O3 were investigated by cyclic voltammetry, chronoamperometry and open circuit measurements. Electrolytes and electrodes were examined after neodymium electrodeposition by optical microscopy and XRD. It was found that tungsten and molybdenum working electrodes behave identically during neodymium complexed ion reduction processes. Their reversible potentials in the electrolytes used differed only by 10 mV, and so did the potentials of the neodymium ion reduction processes. The recorded results indicated that the Nd(III) ions in the melts were reduced in two steps: Nd(III) → Nd(II) and Nd(II) → Nd(0). These consecutive processes are predominantly mass transfer controlled. Electrolytically obtained metal appeared to accumulate on the cathode and no metal neodymium was recorded in the solidified electrolyte placed close to the cathode after completed electrodeposition process. However, it was found that NdF2 formed by the disproportionation reaction between Nd(III) and that deposited Nd(0) coexists with other complex components in the electrolytes used.
T2  - International Journal of Electrochemical Science
T1  - Study of Nd deposition onto W and Mo Cathodes from Molten Oxide-Fluoride Electrolyte
VL  - 15
IS  - 7
SP  - 7039
EP  - 7052
DO  - 10.20964/2020.07.82
ER  - 

@article{
author = "Cvetković, Vesna S. and Vukićević, Nataša and Feldhaus, Dominic and Barudžija, Tanja and Stevanović, Jasmina and Friedrich, Bernd and Jovićević, Jovan J.",
year = "2020",
abstract = "Electrochemical reduction processes of Nd(III) on tungsten and molybdenum electrodes in NdF3+LiF and NdF3+LiF+Nd2O3 were investigated by cyclic voltammetry, chronoamperometry and open circuit measurements. Electrolytes and electrodes were examined after neodymium electrodeposition by optical microscopy and XRD. It was found that tungsten and molybdenum working electrodes behave identically during neodymium complexed ion reduction processes. Their reversible potentials in the electrolytes used differed only by 10 mV, and so did the potentials of the neodymium ion reduction processes. The recorded results indicated that the Nd(III) ions in the melts were reduced in two steps: Nd(III) → Nd(II) and Nd(II) → Nd(0). These consecutive processes are predominantly mass transfer controlled. Electrolytically obtained metal appeared to accumulate on the cathode and no metal neodymium was recorded in the solidified electrolyte placed close to the cathode after completed electrodeposition process. However, it was found that NdF2 formed by the disproportionation reaction between Nd(III) and that deposited Nd(0) coexists with other complex components in the electrolytes used.",
journal = "International Journal of Electrochemical Science",
title = "Study of Nd deposition onto W and Mo Cathodes from Molten Oxide-Fluoride Electrolyte",
volume = "15",
number = "7",
pages = "7039-7052",
doi = "10.20964/2020.07.82"
}

Cvetković, V. S., Vukićević, N., Feldhaus, D., Barudžija, T., Stevanović, J., Friedrich, B.,& Jovićević, J. J.. (2020). Study of Nd deposition onto W and Mo Cathodes from Molten Oxide-Fluoride Electrolyte. in International Journal of Electrochemical Science, 15(7), 7039-7052.
https://doi.org/10.20964/2020.07.82

Cvetković VS, Vukićević N, Feldhaus D, Barudžija T, Stevanović J, Friedrich B, Jovićević JJ. Study of Nd deposition onto W and Mo Cathodes from Molten Oxide-Fluoride Electrolyte. in International Journal of Electrochemical Science. 2020;15(7):7039-7052.
doi:10.20964/2020.07.82 .

Cvetković, Vesna S., Vukićević, Nataša, Feldhaus, Dominic, Barudžija, Tanja, Stevanović, Jasmina, Friedrich, Bernd, Jovićević, Jovan J., "Study of Nd deposition onto W and Mo Cathodes from Molten Oxide-Fluoride Electrolyte" in International Journal of Electrochemical Science, 15, no. 7 (2020):7039-7052,
https://doi.org/10.20964/2020.07.82 . .

TY  - JOUR
AU  - Cvetković, Vesna S.
AU  - Feldhaus, Dominic
AU  - Vukićević, Nataša
AU  - Barudžija, Tanja
AU  - Friedrich, Bernd
AU  - Jovićević, Jovan N.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8971
AB  - Neodymium was electrochemically deposited from NdF3–LiF–Nd2O3 molten salt electrolyte onto the Mo electrode at temperatures close to 1273 K. Cyclic voltammetry and chronoamperometry measurements were the applied electrochemical methods. Metallic neodymium is obtained by potentiostatic deposition. The optical microscopy and XRD were used to analyze the electrolyte, the working electrode surface, and the deposit on the electrode. It was established that Nd(III) ions were reduced to Nd metals in two steps: Nd(III) + e− → Nd(II) at potential ≈−0.55 V vs. W and Nd(II) + 2e− → Nd(0) at ≈−0.83 V vs. W. Both of these processes are reversible and under mass transfer control. Upon deposition under the regime of relatively small deposition overpotential of −0.10 V to −0.20 V, and after the electrolyte was cooled off, Nd metal was observed at the surface of the Mo electrode. CO and CF4 were gases registered as being evolved at the anode. CO and CF4 evolution were observed in quantities below 600 ppm and 10 ppm, respectively
T2  - Metals
T1  - Investigation on the Electrochemical Behaviour and Deposition Mechanism of Neodymium in NdF3–LiF–Nd2O3 Melt on Mo Electrode
VL  - 10
IS  - 5
SP  - 576
DO  - 10.3390/met10050576
ER  - 

@article{
author = "Cvetković, Vesna S. and Feldhaus, Dominic and Vukićević, Nataša and Barudžija, Tanja and Friedrich, Bernd and Jovićević, Jovan N.",
year = "2020",
abstract = "Neodymium was electrochemically deposited from NdF3–LiF–Nd2O3 molten salt electrolyte onto the Mo electrode at temperatures close to 1273 K. Cyclic voltammetry and chronoamperometry measurements were the applied electrochemical methods. Metallic neodymium is obtained by potentiostatic deposition. The optical microscopy and XRD were used to analyze the electrolyte, the working electrode surface, and the deposit on the electrode. It was established that Nd(III) ions were reduced to Nd metals in two steps: Nd(III) + e− → Nd(II) at potential ≈−0.55 V vs. W and Nd(II) + 2e− → Nd(0) at ≈−0.83 V vs. W. Both of these processes are reversible and under mass transfer control. Upon deposition under the regime of relatively small deposition overpotential of −0.10 V to −0.20 V, and after the electrolyte was cooled off, Nd metal was observed at the surface of the Mo electrode. CO and CF4 were gases registered as being evolved at the anode. CO and CF4 evolution were observed in quantities below 600 ppm and 10 ppm, respectively",
journal = "Metals",
title = "Investigation on the Electrochemical Behaviour and Deposition Mechanism of Neodymium in NdF3–LiF–Nd2O3 Melt on Mo Electrode",
volume = "10",
number = "5",
pages = "576",
doi = "10.3390/met10050576"
}

Cvetković, V. S., Feldhaus, D., Vukićević, N., Barudžija, T., Friedrich, B.,& Jovićević, J. N.. (2020). Investigation on the Electrochemical Behaviour and Deposition Mechanism of Neodymium in NdF3–LiF–Nd2O3 Melt on Mo Electrode. in Metals, 10(5), 576.
https://doi.org/10.3390/met10050576

Cvetković VS, Feldhaus D, Vukićević N, Barudžija T, Friedrich B, Jovićević JN. Investigation on the Electrochemical Behaviour and Deposition Mechanism of Neodymium in NdF3–LiF–Nd2O3 Melt on Mo Electrode. in Metals. 2020;10(5):576.
doi:10.3390/met10050576 .

Cvetković, Vesna S., Feldhaus, Dominic, Vukićević, Nataša, Barudžija, Tanja, Friedrich, Bernd, Jovićević, Jovan N., "Investigation on the Electrochemical Behaviour and Deposition Mechanism of Neodymium in NdF3–LiF–Nd2O3 Melt on Mo Electrode" in Metals, 10, no. 5 (2020):576,
https://doi.org/10.3390/met10050576 . .