High-pressure experimental and theoretical investigations on the fluorite structured compoundAuAl2

Abstract

Diamond anvil cell ͑DAC͒ based resistance measurements are carried out in AuAl 2 to the pressures of about 25 GPa for the first time. The data indicate possibility of phase transition around 12 GPa. High pressure data obtained using Elettra synchrotron source confirm the transformation of AuAl 2 from ambient CaF 2 to orthorhombic phase. The high precision P-V data when transformed to universal equation of state does not show any deviation from linearity. The first principles electronic band structure calculations up to these pressures in the cubic phase do not reveal any change corroborating the experimental findings of nonobservation of electronic topological transition in this compound.

Elastic and thermodynamic properties of AuAl2 under pressures

“…1. It is found that the calculated equation of state of AuAl 2 in the cubic fluorite structure is in agreement with the available experimental of Garg et al [25] and theoretical data of Verma et al [26]. Our calculated lattice constant and bulk modulus agree well with the latest theoretical data [26].…”

“…Tütüncü et al investigated the electronic and dynamical properties of AuAl 2 using first-principles [24]. Garg et al also investigated the effect of pressure on the structure and electronic of AuAl 2 performing experimental and theoretical investigations [25]. Verma et al confirmed the high-pressure orthorhombic phase of AuAl 2 using projector augmented wave (PAW) pseudopotentials method [26].…”

Phase stability of intermetallic PtIn2 under pressure: An in-situ transport, structural and first principles investigations

“…1 A small group of intermetallics with substantial covalent bonding are also known. 7 Evidence of disorder at high pressure was also observed as the broadening of x-ray diffraction lines. While the fluorite is the stable form at room temperature for all the Au compounds and PtAl 2 , it occurs as the high temperature modification for PtGa 2 and PtIn 2 .…”

LiCrO2 Under Pressure: In-Situ Structural and Vibrational Studies

“…Electrical resistance measurements up to a maximum pressure of 10 GPa were made using an opposed Bridgman anvil set-up with 12-mm diameter tungsten carbide anvils [41] that is mounted in a hydraulic press. A pair of pyrophyllite gaskets, with a thickness 200 µm each, and with a central hole of 3 mm in diameter, was employed as the pressure chamber.…”