STRUCTURAL PHASE TRANSITIONS AND MECHANICAL PROPERTIES OF OsO2 UNDER HIGH PRESSURE

2010 ◽  
Vol 24 (22) ◽  
pp. 4269-4279 ◽  
Author(s):  
YONGCHENG LIANG ◽  
ANHU LI ◽  
QIUHONG SONG
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Phase Transitions ◽  
First Principles ◽  
Structural Phase ◽  
Fluorite Phase ◽  
Structural Phase Transitions ◽  
Pseudopotential Calculations ◽  
Excellent Candidate ◽  
High Bulk

The structural phase transitions, mechanical properties and electronic structures of OsO 2 under high pressure are systemically investigated by the first-principles plane-wave basis pseudopotential calculations. The possible pressure-induced transition sequence in OsO 2 may be the rutile, pyrite and fluorite phases, and the stable CaCl 2 structure is not found. The fluorite phase has high bulk modulus (355.3 GPa), large shear modulus G (267.9 GPa), and huge elastic constant C44 (292.7 GPa), and consequently is an excellent candidate of superhard materials. Crystal structures, valence electron densities, band structures, DOS and PDOS of the rutile, pyrite and fluorite phases of OsO 2 have also been carefully analyzed to elucidate their mechanical properties.

First Principles Investigations on the Controversy of Structural Phase Transitions in Thorium Dialuminide under Pressure

2021 ◽  
Author(s):  
Ashok Kumar Verma ◽  
Paritosh Modak
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Pressure ◽  
Phase Transitions ◽  
First Principles ◽  
Structural Phase ◽  
First Principles Calculations ◽  
Structural Phase Transitions ◽  
Structural Aspects

We study the high pressure structural aspects of thorium dialuminide, ThAl2, by performing evolutionary crystal structure searches and first principles calculations. We predict a phase transition from the ambient AlB2-type...

Structural phase transitions of LaScO3 from first principles

2021 ◽  
Vol 26 ◽  
pp. 102048
Author(s):  
Craig A.J. Fisher ◽  
Ayako Taguchi ◽  
Takafumi Ogawa ◽  
Akihide Kuwabara
Keyword(s):  
Phase Transitions ◽  
First Principles ◽  
Structural Phase ◽  
Structural Phase Transitions

Crystal structure, compressibility and possible phase transitions in \boldvarepsilon-FeSi studied by first-principles pseudopotential calculations

1999 ◽  
Vol 55 (4) ◽  
pp. 484-493 ◽  
Author(s):  
Lidunka Vočadlo ◽  
Geoffrey D. Price ◽  
I. G. Wood
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Phase Transitions ◽  
First Principles ◽  
Stable Phase ◽  
Third Order ◽  
First Derivative ◽  
Pseudopotential Calculations ◽  
Cscl Type ◽  
Murnaghan Equation

An investigation of the relative stability of the FeSi structure and of some hypothetical polymorphs of FeSi has been made by first-principles pseudopotential calculations. It has been shown that the observed distortion from ideal sevenfold coordination is essential in stabilizing the FeSi structure relative to one of the CsCl type. Application of high pressure to FeSi is predicted to produce a structure having nearly perfect sevenfold coordination. However, it appears that FeSi having a CsCl-type structure will be the thermodynamically most stable phase for pressures greater than 13 GPa. Fitting of the calculated internal energy vs volume for the FeSi structure to a third-order Birch–Murnaghan equation of state led to values, at T = 0 K, for the bulk modulus, K 0, and for its first derivative with respect to pressure, K 0′, of 227 GPa and 3.9, respectively.

Pseudopotential Calculations of Structural Properties of Solids

1985 ◽  
Vol 63 ◽  
Author(s):  
Marvin L. Cohen
Keyword(s):  
Phase Transitions ◽  
Structural Phase ◽  
Vibrational Properties ◽  
Structural Phase Transitions ◽  
Superconducting Properties ◽  
Lattice Constants ◽  
Pseudopotential Calculations ◽  
Pseudopotential Approach ◽  
Cohesive Energies

ABSTRACTThrough the development of a total energy pseudopotential approach, it has become possible to compute structural, electronic, and vibrational properties of solids using only the atomic numbers and atomic masses of the constituent atoms as input. The method has been applied to semiconductors, insulators, and metals; and agreement with experiment for most properties is usually within a few percent.Applications include the determination of lattice constants for specific structural phases, properties of structural phase transitions, cohesive energies, bulk moduli, lattice vibrational spectra, electron-lattice interaction parameters, and electronic and superconducting properties. A recent example is the prediction of superconductivity in highly condensed hexagonal silicon which was subsequently found experimentally.

scholarly journals High-pressure structural phase transitions in tellurium

1988 ◽  
Vol 37 (14) ◽  
pp. 8499-8501 ◽  
Author(s):  
G. Parthasarathy ◽  
W. B. Holzapfel
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
Structural Phase ◽  
Structural Phase Transitions

Structural Phase Transitions, Electronic Properties, and Hardness of RuB4 under High Pressure in Comparison with FeB4 and OsB4

2020 ◽  
Vol 124 (27) ◽  
pp. 14804-14810
Author(s):  
Komsilp Kotmool ◽  
Prutthipong Tsuppayakorn-aek ◽  
Thanayut Kaewmaraya ◽  
Udomsilp Pinsook ◽  
Rajeev Ahuja ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
Electronic Properties ◽  
Structural Phase ◽  
Structural Phase Transitions

scholarly journals Structural phase transitions in VSe2: energetics, electronic structure and magnetism

2019 ◽  
Vol 21 (40) ◽  
pp. 22647-22653 ◽  
Author(s):  
Georgy V. Pushkarev ◽  
Vladimir G. Mazurenko ◽  
Vladimir V. Mazurenko ◽  
Danil W. Boukhvalov
Keyword(s):  
Electronic Structure ◽  
Phase Transitions ◽  
Electronic Properties ◽  
First Principles ◽  
Structural Phase ◽  
First Principles Calculations ◽  
Structural Phase Transitions

First principles calculations of the magnetic and electronic properties of VSe2 describing the transition between two structural phases (H,T) were performed.

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