Pressure-induced order–disorder transitions in β-In₂S₃: an experimental and theoretical study of structural and vibrational properties

Abstract

This joint experimental and theoretical study of the structural and vibrational properties of β-In2S3 upon compression shows that this tetragonal defect spinel undergoes two reversible pressure-induced order–disorder transitions up to 20 GPa.

High-Pressure Synthesis of β- and α-In2Se3-Like Structures in Ga2S3

“…Since experimentally the R -3 m phase appears from 12 GPa on at RT depending on the hydrostatic conditions as exemplified in this work and in refs and our lattice dynamics calculations at 0 K suggest that temperature also plays a role in stabilizing this phase at RT at smaller pressures than theoretically predicted to be stable. Therefore, we conclude that the R -3 m phase is reached in Ga 2 S 3 at RT and HP in the same way as the R 3̅ m phase is found in In 2 Se 3 at RT and HP …”

“…However, most binary Ga-based OVCs show HP-PTs characterized by a relocation of the vacancies rather than a mixture of cations and vacancies (the exception seems to be β-Ga 2 Se 3 that undergoes a PT to the DR phase). In this case, the interlayer space in φ-Ga 2 S 3 and β′-Ga 2 S 3 can be considered as planes of vacancies, as recently suggested in refs and . Another difference between both families of chalcogenides is that ternary A Ga 2 X 4 chalcogenides only exhibit DR phases at HP (the R -3 m phase has never been found).…”

“…Additional support to the observation of the DZ phase in decompressed Ga 2 S 3 comes from the fact that both β′-Ga 2 S 3 and φ-Ga 2 S 3 show vacancies in the structure, so an order–disorder PT can occur on the downstroke. In this context, we must note that β′-Ga 2 S 3 is a distorted rocksalt phase with a 6-fold coordinated cation that has a plane of vacancies forming the interlayer space. , Similarly, φ-Ga 2 S 3 has cations with 6-fold and 4-fold coordination and also has the same plane of vacancies at the interlayer space. Therefore, a PT to the DZ phase on downstroke in α′-Ga 2 S 3 is highly possible in its way to attain a 4-fold cation coordination at RC if no thermal energy is added to the system.…”

“…Therefore, we conclude that the R-3m phase is reached in Ga 2 S 3 at RT and HP in the same way as the R3̅ m phase is found in In 2 Se 3 at RT and HP. 99 4.1.2. Decompression.…”

Pressure-induced disorder and nanosizing inhibits superconductivity in In2Te3

“…Pressure-quenched superconductivity induced by electronic phase transitions under pressure in Weyl semimetal NbP was reported in previous work [10]. In addition, investigations on the electronic structural transition of chalcogenides, the reversibility of transition, the relevance of hydrostatic pressure and phase transition related to superconductivity were also explored [11][12][13]. However, establishing a connection between disorder and high-pressure superconductivity remains a challenge from the perspective of high-pressure studies.…”