Pressure-induced superconductivity and structure phase transition in Pt2HgSe3

AbstractRecently monolayer jacutingaite (Pt2HgSe3), a naturally occurring exfoliable mineral, discovered in Brazil in 2008, has been theoretically predicted as a candidate quantum spin Hall system with a 0.5 eV band gap, while the bulk form is one of only a few known dual-topological insulators that may host different surface states protected by symmetries. In this work, we systematically investigate both structure and electronic evolution of bulk Pt2HgSe3 under high pressure up to 96 GPa. The nontrivial topology is theoretically stable, and persists up to the structural phase transition observed in the high-pressure regime. Interestingly, we found that this phase transition is accompanied by the appearance of superconductivity at around 55 GPa and the critical transition temperature Tc increases with applied pressure. Our results demonstrate that Pt2HgSe3 with nontrivial topology of electronic states displays a ground state upon compression and raises potentials in application to the next-generation spintronic devices.

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DFT Calculations of the Structural, Mechanical, and Electronic Properties of TiV Alloy Under High Pressure

Symmetry ◽

10.3390/sym11080972 ◽

2019 ◽

Vol 11 (8) ◽

pp. 972 ◽

Cited By ~ 1

Author(s):

Fang Yu ◽

Yu Liu

Keyword(s):

Phase Transition ◽

High Pressure ◽

Electronic Properties ◽

Structural Phase Transition ◽

Density Functional ◽

Structural Phase ◽

Applied Pressure ◽

Functional Theory ◽

The Density Functional Theory ◽

Dimensionless Ratio

A calculation program based on the density functional theory (DFT) is applied to study the structural, mechanical, and electronic properties of TiV alloys with symmetric structure under high pressure. We calculate the dimensionless ratio, elastic constants, shear modulus, Young’s modulus, bulk modulus, ductile-brittle transition, material anisotropy, and Poisson’s ratio as functions of applied pressure. Results suggest that the critical pressure of structural phase transition is 42.05 GPa for the TiV alloy, and structural phase transition occurs when the applied pressure exceeds 42.05 GPa. High pressure can improve resistance to volume change, as well as the ductility and atomic bonding, but the strongest resistances to elastic and shear deformation occur at P = 5 GPa for TiV alloy. Furthermore, the results of the density of states (DOS) indicate that the TiV alloy presents metallicity. High pressure disrupts the structural stability of the TiV alloy with symmetry, thereby inducing structural phase transition.

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Pressure-Induced Structural Phase Transition and Metallization in Ga2Se3 up to 40.2 GPa under Non-Hydrostatic and Hydrostatic Environments

Crystals ◽

10.3390/cryst11070746 ◽

2021 ◽

Vol 11 (7) ◽

pp. 746

Author(s):

Meiling Hong ◽

Lidong Dai ◽

Haiying Hu ◽

Xinyu Zhang

Keyword(s):

Phase Transition ◽

Electrical Conductivity ◽

High Pressure ◽

Phase Transformation ◽

Transport Properties ◽

Electrical Transport ◽

Structural Phase ◽

Structure Evolution ◽

Systematic Research ◽

Electrical Transport Properties

A series of investigations on the structural, vibrational, and electrical transport characterizations for Ga2Se3 were conducted up to 40.2 GPa under different hydrostatic environments by virtue of Raman scattering, electrical conductivity, high-resolution transmission electron microscopy, and atomic force microscopy. Upon compression, Ga2Se3 underwent a phase transformation from the zinc-blende to NaCl-type structure at 10.6 GPa under non-hydrostatic conditions, which was manifested by the disappearance of an A mode and the noticeable discontinuities in the pressure-dependent Raman full width at half maximum (FWHMs) and electrical conductivity. Further increasing the pressure to 18.8 GPa, the semiconductor-to-metal phase transition occurred in Ga2Se3, which was evidenced by the high-pressure variable-temperature electrical conductivity measurements. However, the higher structural transition pressure point of 13.2 GPa was detected for Ga2Se3 under hydrostatic conditions, which was possibly related to the protective influence of the pressure medium. Upon decompression, the phase transformation and metallization were found to be reversible but existed in the large pressure hysteresis effect under different hydrostatic environments. Systematic research on the high-pressure structural and electrical transport properties for Ga2Se3 would be helpful to further explore the crystal structure evolution and electrical transport properties for other A2B3-type compounds.

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High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

Journal of Materials Chemistry C ◽

10.1039/d0tc06004f ◽

2021 ◽

Author(s):

Linfei Yang ◽

Jianjun Jiang ◽

Lidong Dai ◽

Haiying Hu ◽

Meiling Hong ◽

...

Keyword(s):

Phase Transition ◽

Raman Spectroscopy ◽

High Pressure ◽

Structural Properties ◽

Structural Phase Transition ◽

First Principles ◽

Theoretical Calculations ◽

Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

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