Experimental and theoretical evidence of the temperature-induced wurtzite to rocksalt phase transition in GaN under high pressure

2020 ◽  
Vol 102 (23) ◽  
Author(s):  
Bohdan Sadovyi ◽  
Małgorzata Wierzbowska ◽  
Svitlana Stelmakh ◽  
Silvia Boccato ◽  
Stanislaw Gierlotka ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Rocksalt Phase ◽  
Theoretical Evidence

The Theoretical Study of the Cinnabar-to-Rocksalt Phase Transitions of HgTe and CdTe under High Pressure

2014 ◽  
Vol 1004-1005 ◽  
pp. 1608-1614 ◽  
Author(s):  
Xi Duo Hu ◽  
De Hai Zhu ◽  
Zhi Feng Zeng ◽  
Shao Rui Sun
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Phase Transitions ◽  
Theoretical Study ◽  
Chain Structure ◽  
Two Phase ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
First Order ◽  
Rocksalt Phase

We performed the first-principle calculation to study the structures of cinnabar phase and the Cinnabar-to-rocksalt Phase transitions of HgTe and CdTe under high pressure. The calculated results show that for HgTe, the zincblende-to-cinnabar phase transition is under 2.2GPa, and the cinnabar-to-rocksalt phase transition is under 5.5 GPa; For CdTe, the two phase transitions occur under 4.0 GPa and 4.9 GPa, respectively, which well agree with the experimental results. The cinnabar-to-rocksalt phase transitions of most compounds, including HgTe and CdTe, except HgS are of first-order, and it is due to that their cinnabar phases are not chain structure as HgS and there are no relaxation process before the phase transition.

High-pressure structure of gallium nitride: Wurtzite-to-rocksalt phase transition

1993 ◽  
Vol 47 (19) ◽  
pp. 12925-12928 ◽  
Author(s):  
Hui Xia ◽  
Qing Xia ◽  
Arthur L. Ruoff
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Gallium Nitride ◽  
Rocksalt Phase

scholarly journals Pressure-Induced Phase Transition in Thiol-Capped CdTe Nanoparticles

2008 ◽  
Vol 8 (12) ◽  
pp. 6528-6532 ◽  
Author(s):  
Fanxin Wu ◽  
Joseph M. Zaug ◽  
Christopher E. Young ◽  
Jin Z. Zhang
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Shape Change ◽  
Transition Pressure ◽  
Cdte Nanoparticles ◽  
Fluorescence Measurements ◽  
Rocksalt Phase ◽  
Phase Transition Pressure ◽  
Solid Form ◽  
Enhanced Stability

Phase transitions for CdTe nanoparticles (NPs) under high pressure up to 37.0 GPa have been studied using fluorescence measurements. The phase transition from cinnarbar to rocksalt phase has been observed in CdTe NPs solution at 5.8 GPa, which is much higher than the phase transition pressure of bulk CdTe (3.8 GPa) and that of CdTe NPs in solid form (0.8 GPa). CdTe NPs solution therefore shows elevated phase transition pressure and enhanced stability against pressure compared with bulk CdTe and CdTe NPs in solid forms. The enhanced stability of CdTe NPs solution has been attributed to possible shape change in the phase transition and/or inhomogeneous strains in nanoparticle solutions.

scholarly journals Orpiment under compression: metavalent bonding at high pressure

2020 ◽  
Vol 22 (6) ◽  
pp. 3352-3369 ◽  
Author(s):  
Vanesa Paula Cuenca-Gotor ◽  
Juan Ángel Sans ◽  
Oscar Gomis ◽  
Andres Mujica ◽  
Silvana Radescu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Strong Change ◽  
Isostructural Phase Transition

Orpiment (α-As2S3) under compression reports a strong change in the coordination of As atoms at 25 GPa, which can be ascribed to an isostructural phase transition. These changes are consistent with the formation of metavalent bonds in orpiment.

scholarly journals Crystal and electronic structure engineering of tin monoxide by external pressure

2021 ◽  
Author(s):  
Kun Li ◽  
Junjie Wang ◽  
Vladislav A. Blatov ◽  
Yutong Gong ◽  
Naoto Umezawa ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Band Gap ◽  
High Pressures ◽  
Low Pressure ◽  
Widespread Application ◽  
Space Group ◽  
Tin Monoxide ◽  
High Possibility ◽  
Pressure Phase

AbstractAlthough tin monoxide (SnO) is an interesting compound due to its p-type conductivity, a widespread application of SnO has been limited by its narrow band gap of 0.7 eV. In this work, we theoretically investigate the structural and electronic properties of several SnO phases under high pressures through employing van der Waals (vdW) functionals. Our calculations reveal that a metastable SnO (β-SnO), which possesses space group P21/c and a wide band gap of 1.9 eV, is more stable than α-SnO at pressures higher than 80 GPa. Moreover, a stable (space group P2/c) and a metastable (space group Pnma) phases of SnO appear at pressures higher than 120 GPa. Energy and topological analyses show that P2/c-SnO has a high possibility to directly transform to β-SnO at around 120 GPa. Our work also reveals that β-SnO is a necessary intermediate state between high-pressure phase Pnma-SnO and low-pressure phase α-SnO for the phase transition path Pnma-SnO →β-SnO → α-SnO. Two phase transition analyses indicate that there is a high possibility to synthesize β-SnO under high-pressure conditions and have it remain stable under normal pressure. Finally, our study reveals that the conductive property of β-SnO can be engineered in a low-pressure range (0–9 GPa) through a semiconductor-to-metal transition, while maintaining transparency in the visible light range.

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

Crystals ◽  
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.

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

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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