New Pressure-Induced Phase Transitions in Bismuthinite

• Published in: JETP letters Vol. 114; no. 8; pp. 470 - 474
• Main Authors: Brazhkin, V. V., Dyuzheva, T. I., Zibrov, I. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.10.2021; Springer Nature B.V
• Subjects: Antimony; Atomic; Biological and Medical Physics; Biophysics; Bismuth sulfides; Chalcogenides; Composition; Condensed Matter; Crystal structure; High pressure; High temperature; Molecular; Optical and Plasma Physics; Particle and Nuclear Physics; Phase transitions; Physics; Physics and Astronomy; Pressure effects; Quantum Information Technology; Solid State Physics; Spintronics; Stoichiometry; Thermal instability
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364021200054

The study of the effect of high pressure and high temperature on the crystal structure of Bi 2 S 3 has revealed that Bi 2 S 3 decays chemically at p = 6–8 GPa and T = 625–1050°C through the Bi 2 S 3 → BiS 2 + Bi + S reaction with the formation of BiS 2 -I ( a = (15.74 ± 0.01) Å, b = (4.026 ± 0.004) Å, c = (11.34 ± 0.01) Å, , D x = 6.36 g/cm 3 , V / Z = 71.31 Å 3 ), and a new metastable high-pressure phase BiS 2 -II with mmm symmetry ( a = (8.45 ± 0.01) Å, b = (10.26 ± 0.01) Å, c = (5.87 ± 0.007) Å, D x = 7.12 g/cm 3 , V / Z = 63.695 Å 3 , Δ V / V 0 = 0.11) appears at p = 8–8.5 GPa and T ≥ 1100–1300°C. The BiS 2 -II phase in mixture with the BiS 2 -I phase is also formed in the Bi + S(1 : 2) composition at the same pressures and temperatures. Chalcogenides of the V 2 VI 3 composition (V = As, Sb, Bi; VI = S, Se) demonstrate a pronounced tendency to thermal instability with the formation of chalcogenides with “incorrect” VVI 2 stoichiometry such as AsS 2 , AsSe 2 , BiS 2 -I, BiS 2 -II, and BiSe 2 , but the layered structures of these metastable high-pressure phases are different. It can be assumed that the pressure-induced V 2 VI 3 → VVI 2 + VVI and V 2 VI 3 → VVI 2 + V + VI decay reactions into compounds with incorrect stoichiometry are a general property of these chalcogenides.