Ab-initio Investigations of R3c to Pm3m Transition in RAlO_3 (La, Pr and Nd) Perovskites Under Pressure

摘要

The structural phase transition in RAlO_3 (R = La, Pr and Nd) perovskites has been investigated using density functional theory with generalized gradient approximated exchange-correlation. Ambient pressure rhombohedral structure (R3c) transforms to a cubic structure (Pm3m) under pressure and the estimated transition pressures are 40, 92 and 95 GPa for LaAlO_3, PrAlO_3 and NdAlO_3, respectively. Calculated ground state properties and equation of states are in good agreement with available experimental data.