Unraveling microstrain-promoted structural evolution and thermally driven phase transition in c−Sc2O3 nanocrystals at high pressure

2020 ◽  
Vol 102 (21) ◽  
Author(s):  
Yongtao Zou ◽  
Mu Li ◽  
Wei Zhang ◽  
Cangtao Zhou ◽  
Tony Yu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Structural Evolution ◽  
Thermally Driven

scholarly journals Anomalous anisotropic compression behavior of superconducting CrAs under high pressure

2015 ◽  
Vol 112 (48) ◽  
pp. 14766-14770 ◽  
Author(s):  
Zhenhai Yu ◽  
Wei Wu ◽  
Qingyang Hu ◽  
Jinggeng Zhao ◽  
Chunyu Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Structural Evolution ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Band Model ◽  
X Ray Diffraction ◽  
Compression Behavior ◽  
Phase Transition Pressure ◽  
Nonmonotonic Change

CrAs was observed to possess the bulk superconductivity under high-pressure conditions. To understand the superconducting mechanism and explore the correlation between the structure and superconductivity, the high-pressure structural evolution of CrAs was investigated using the angle-dispersive X-ray diffraction (XRD) method. The structure of CrAs remains stable up to 1.8 GPa, whereas the lattice parameters exhibit anomalous compression behaviors. With increasing pressure, the lattice parameters a and c both demonstrate a nonmonotonic change, and the lattice parameter b undergoes a rapid contraction at ∼0.18−0.35 GPa, which suggests that a pressure-induced isostructural phase transition occurs in CrAs. Above the phase transition pressure, the axial compressibilities of CrAs present remarkable anisotropy. A schematic band model was used to address the anomalous compression behavior of CrAs. The present results shed light on the structural and related electronic responses to high pressure, which play a key role toward understanding the superconductivity of CrAs.

scholarly journals Quantum simulation of thermally-driven phase transition and oxygen K-edge x-ray absorption of high-pressure ice

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Dongdong Kang ◽  
Jiayu Dai ◽  
Huayang Sun ◽  
Yong Hou ◽  
Jianmin Yuan
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Quantum Simulation ◽  
X Ray ◽  
Thermally Driven ◽  
X Ray Absorption

scholarly journals Structural evolution and phase transition mechanism of $$\hbox {MoSe}_2$$ under high pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yifeng Xiao ◽  
Shi He ◽  
Mo Li ◽  
Weiguo Sun ◽  
Zhichao Wu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Phonon Dispersion ◽  
Electronic Band Structure ◽  
Ambient Pressure ◽  
Structural Evolution ◽  
Ultrahigh Pressure ◽  
Ground State Structure ◽  
Electronic Band ◽  
Transition Mechanism

Abstract$$\hbox {MoSe}_2$$ MoSe 2 is a layered transition-metal dichalcogenide (TMD) with outstanding electronic and optical properties, which is widely used in field-effect transistor (FET). Here the structural evolution and phase transition of $$\hbox {MoSe}_2$$ MoSe 2 under high pressure are systematically studied by CALYPSO structural search method and first-principles calculations. The structural evolutions of $$\hbox {MoSe}_2$$ MoSe 2 show that the ground state structure under ambient pressure is the experimentally observed P6$$_3$$ 3 /mmc phase, which transfers to R3m phase at 1.9 GPa. The trigonal R3m phase of $$\hbox {MoSe}_2$$ MoSe 2 is stable up to 72.1 GPa, then, it transforms into a new P6$$_3$$ 3 /mmc phase with different atomic coordinates of Se atoms. This phase is extremely robust under ultrahigh pressure and finally changes to another trigonal R-3m phase under 491.1 GPa. The elastic constants and phonon dispersion curves indicate that the ambient pressure phase and three new high-pressure phases are all stable. The electronic band structure and projected density of states analyses reveal a pressure induced semiconducting to metallic transition under 72.1 GPa. These results offer a detailed structural evolution and phase diagram of $$\hbox {MoSe}_2$$ MoSe 2 under high pressure, which may also provide insights for exploration other TMDs under ultrahigh pressure.

Elastic behavior, phase transition, and pressure induced structural evolution of analcime

2006 ◽  
Vol 91 (4) ◽  
pp. 568-578 ◽  
Author(s):  
G. D. Gatta ◽  
F. Nestola ◽  
T. B. Ballaran
Keyword(s):  
Phase Transition ◽  
Structural Evolution ◽  
Elastic Behavior

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.

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