High pressure transport, structural, and first principles investigations on the fluorite structured intermetallic, PtAl2

作者：Garg Alka B^*; Modak P; Vijayakumar V

来源：Journal of Applied Physics, 2012, 111(1): 013507.

DOI：10.1063/1.3673522

Phase stability of intermetallic PtAl2 at high pressure and ambient temperature has been investigated using synchrotron based angle dispersive x-ray diffraction technique, electrical transport (resistance and thermoelectric power) measurements, and first principles electronic structure calculations. The electrical resistance falls approximately by 15% near 4.5 GPa. This feature is also reflected in the thermoelectric power measurements as a dip in the same pressure region. Consistent with these observations, the x-ray diffraction data show a structural phase transition from ambient cubic phase to an orthorhombic phase with a 5% volume reduction. Beyond 7.2 GPa, the diffraction peaks are broadened indicating the presence of disorder at high pressure. Ab initio structural relaxations and total energy calculations predict the cubic to orthorhombic phase transitions at 6.2GPa.

• 出版日期2012-1-1