Pressure dependence of band-gap and phase transitions in bulk CuX (X = Cl, Br, I)

Journal Article · Fri May 06 00:00:00 EDT 2016 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4946362· OSTI ID:22606430

Azhikodan, Dilna; Nautiyal, Tashi ^[1]; Sharma, S. ^[2]

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1. Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand - 247 667 (India)
2. Max-Planck-Institut of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany)

Usually a phase transition, in theoretical studies, is explored or verified by studying the total energy as a function of the volume considering various plausible phases. The intersection point, if any, of the free energy vs. volume curves for the different phases is then the indicator of the phase transition(s). The question is, can the theoretical study of a single phase alone indicate a phase transition? i.e. can we look beyond the phase under consideration through such a study? Using density-functional theory, we report a novel approach to suggest phase transition(s) through theoretical study of a single phase. Copper halides have been engaged for this study. These are direct band-gap semiconductors, with zinc blende structure at ambient conditions, and are reported to exhibit many phase transitions. We show that the study of volume dependence of energy band-gap in a single phase facilitates looking beyond the phase under consideration. This, when translated to pressures, reflects the phase transition pressures for CuX (X = Cl, Br, I) with an encouraging accuracy. This work thus offers a simple, yet reliable, approach based on electronic structure calculations to investigate new semiconducting materials for phase changes under pressure.

• OSTI ID: 22606430
• Journal Information: AIP Conference Proceedings, Vol. 1728, Issue 1; Conference: ICC 2015: International conference on condensed matter and applied physics, Bikaner (India), 30-31 Oct 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACCURACY
COPPER BROMIDES
COPPER CHLORIDES
COPPER COMPOUNDS
COPPER HALIDES
COPPER IODIDES
CRYSTAL-PHASE TRANSFORMATIONS
DENSITY
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
FREE ENERGY
PHASE TRANSFORMATIONS
PRESSURE DEPENDENCE
SEMICONDUCTOR MATERIALS
SIMULATION