Ab initio calculations of the thermodynamics and phase diagram of ScSb

Abstract

The hydrostatic pressure-induced transition phase of ScSb from the sixfold-coordinated NaCl-type (B1) to the eightfold-coordinated CsCl-type (B2) is investigated within the Perdew-Burke-Ernzerhof (PBE) form of generalized gradient approximation. It is found that the transition pressure from the B1 to B2 phase is at 42.8 GPa which agrees with experiment. Through the quasi-harmonic Debye model, the dependences of the relative volume V on the pressure P, the thermal expansion, the Grüneisen parameter ratio, (c -c 0 )/c 0 , the Debye temperature H, and heat capacity C V on the pressure P and temperature T are estimated. The quasi-harmonic Debye model for the first time is used to predict phase diagram of B1 ? B2.

Ab initio investigations of electron correlation effect and phonon dynamics of orthorhombic uranium

“…Obviously, the calculated results accord with previous experimental values as well as other theoretical simulation values . Also, the bulk modulus B and its pressure derivative B′ (Table ) have been estimated by fitting Birch–Murnaghan's equation of state , the present bulk modulus B of α‐U is 139 GPa and its pressure derivative B′ is 5.2810, which are also in reasonable agreement with available other results .…”

FTIR and UV-Visible Absorbance Studies of Hydrothermally Grown ZnO Coated with Polyvinylpyrrolidone

“…The spectrum of pure PVP exhibited five absorption peaks located at 3404 cm -1 , 2943 cm -1 , 1649 cm -1 , 1422 cm -1 , and 1288 cm -1 . These are assigned to the O-H stretching vibration, CH 2 unsymmetrical stretching vibration, C=O stretching vibration, CH 2 bending vibration and C-N stretching vibration band, respectively [12][13][14]. Pure ZnO as well as coated ZnO microrods also showed an O-H stretching vibration peak.…”