Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Properties of oxysulfide phases and phase diagram of the Nd2S3–Nd2O3 system. / Osseni, S.; Andreev, P. O.; Polkovnikov, A. A. и др.
в: Journal of Solid State Chemistry, Том 314, 123438, 10.2022.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Properties of oxysulfide phases and phase diagram of the Nd2S3–Nd2O3 system
AU - Osseni, S.
AU - Andreev, P. O.
AU - Polkovnikov, A. A.
AU - Zakharov, B. A.
AU - Aleksandrovsky, A. S.
AU - Abulkhaev, M. U.
AU - Volkova, S. S.
AU - Kamaev, D. N.
AU - Kovenskiy, I. M.
AU - Nesterova, N. V.
AU - Kudomanov, M. V.
AU - Andreev, O. V.
N1 - Funding Information: This research was funded by the Tyumen Oblast Government , as part of the West-Siberian Interregional Science and Education Center's project No. 89-DON (3) . Publisher Copyright: © 2022 Elsevier Inc.
PY - 2022/10
Y1 - 2022/10
N2 - We have determined the thermal characteristics and optical properties of the sulfide and oxysulfide phases in the Nd2S3 - Nd2O3 system. A congruent melting peak at temperature 1801 ± 4.9 °C with ΔH = 65.2 ± 6.7 kJ/mol was detected for the Nd2S3 compound by the DSC method. The characteristics of the α-Nd2S3 → γ-Nd2S3 polymorphic transition are t = 1183 ± 1.8°С, and ΔH = 7.5 ± 0.3 kJ/mol. The γ-Nd2S3 phase obtained upon cooling during annealing at 800 °C is retained for up to 30 h, and then the γ-Nd2S3 → α-Nd2S3 transition occurs within 20 h. The microhardness of the phases is: α-Nd2S3 H = 451 ± 4 HV; γ-Nd2S3 H = 531 ± 4 HV. It was found by the TG method that the Nd10S14O phase thermally dissociates at temperatures above 1400 °C. The mass loss is 0.5 mass % at 1580 °C and 1.0 mass % at 1620 °C, but the samples remain single-phase ones after cooling. However, two impurity phases γ-Nd2S3-X and Nd2O2S appear in the Nd10S14O samples treated at temperatures above 1620 ± 20 °C. For samples of the Nd10S14O phase annealed in an argon atmosphere at temperatures of 1050, 1400, 1580 °C, a regular decrease in the unit cell parameters and optical band gap was recorded: 1050 °C a = 15.06291(28), c = 19.97864(35), Eg = 2, 63 eV, 1400 °C a = 15.04779(36), c = 19.97160(44), Eg = 2.64 eV; 1580 °C a = 15.03532(48), c = 19.94984(60), Eg = 2.51 eV. The microhardness of Nd10S14O is H = 549 ± 10 HV. The Nd2O2S phase has H = 593 ± 4 HV, Eg = 4.28 eV. The phase diagram of the Nd2S3 - Nd2O3 system from 1000 °C to the melt was constructed. The Nd2O2S phase melts congruently at 2050 ± 30 °C. Eutectics with coordinates 23 mol. % Nd2O3 (0.3484 Nd10S14O + 0.6516 Nd2O2S), t = 1553 ± 1.8°С ΔH = 187 ± 19 J/g; 82 mol. % Nd2O3; (0.54 Nd2O2S + 0.46 Nd2O3), t = 1970 ± 30°С were obtained. The liquidus of the Nd2S3 - Nd2O3 system was built according to DSC data and calculated using the Redlich-Kister equation. The melting enthalpy of Nd2O2S ΔH = 67 kJ/mol was calculated using the Schroeder equation.
AB - We have determined the thermal characteristics and optical properties of the sulfide and oxysulfide phases in the Nd2S3 - Nd2O3 system. A congruent melting peak at temperature 1801 ± 4.9 °C with ΔH = 65.2 ± 6.7 kJ/mol was detected for the Nd2S3 compound by the DSC method. The characteristics of the α-Nd2S3 → γ-Nd2S3 polymorphic transition are t = 1183 ± 1.8°С, and ΔH = 7.5 ± 0.3 kJ/mol. The γ-Nd2S3 phase obtained upon cooling during annealing at 800 °C is retained for up to 30 h, and then the γ-Nd2S3 → α-Nd2S3 transition occurs within 20 h. The microhardness of the phases is: α-Nd2S3 H = 451 ± 4 HV; γ-Nd2S3 H = 531 ± 4 HV. It was found by the TG method that the Nd10S14O phase thermally dissociates at temperatures above 1400 °C. The mass loss is 0.5 mass % at 1580 °C and 1.0 mass % at 1620 °C, but the samples remain single-phase ones after cooling. However, two impurity phases γ-Nd2S3-X and Nd2O2S appear in the Nd10S14O samples treated at temperatures above 1620 ± 20 °C. For samples of the Nd10S14O phase annealed in an argon atmosphere at temperatures of 1050, 1400, 1580 °C, a regular decrease in the unit cell parameters and optical band gap was recorded: 1050 °C a = 15.06291(28), c = 19.97864(35), Eg = 2, 63 eV, 1400 °C a = 15.04779(36), c = 19.97160(44), Eg = 2.64 eV; 1580 °C a = 15.03532(48), c = 19.94984(60), Eg = 2.51 eV. The microhardness of Nd10S14O is H = 549 ± 10 HV. The Nd2O2S phase has H = 593 ± 4 HV, Eg = 4.28 eV. The phase diagram of the Nd2S3 - Nd2O3 system from 1000 °C to the melt was constructed. The Nd2O2S phase melts congruently at 2050 ± 30 °C. Eutectics with coordinates 23 mol. % Nd2O3 (0.3484 Nd10S14O + 0.6516 Nd2O2S), t = 1553 ± 1.8°С ΔH = 187 ± 19 J/g; 82 mol. % Nd2O3; (0.54 Nd2O2S + 0.46 Nd2O3), t = 1970 ± 30°С were obtained. The liquidus of the Nd2S3 - Nd2O3 system was built according to DSC data and calculated using the Redlich-Kister equation. The melting enthalpy of Nd2O2S ΔH = 67 kJ/mol was calculated using the Schroeder equation.
KW - Melting enthalpy
KW - Neodymium oxysulfide
KW - Neodymium sulfide
KW - Optical bandgap
KW - Phase diagram
KW - Structure
UR - http://www.scopus.com/inward/record.url?scp=85135504536&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/afff8b04-3c83-30a0-a6a8-d5b925d70562/
U2 - 10.1016/j.jssc.2022.123438
DO - 10.1016/j.jssc.2022.123438
M3 - Article
AN - SCOPUS:85135504536
VL - 314
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
SN - 0022-4596
M1 - 123438
ER -
ID: 36807266