Phase Transition of Praseodymium Mono-Pnictides Under High Pressure

Abstract

The Phase transition and elastic properties of Praseodymium-monopnictides have been investigated under pressure by means of a modified charge-transfer potential model which incorporates the Coulomb screening due to the delocalization of f-electron of rare-earth atom leading to many-body interactions, along with Coulomb interaction, covalency effect and overlap repulsion extended up to second-nearest neighbours. These compunds undergo transition from NaCl structure to high pressure body-centered tetragonal (BCT) structure (distorted CsCl-type P4/mmm). The calculated values of cohesive energy, lattice constant, phase transition pressure, relative volume collapse. Present model explains the Cauchy's discrepancy correctly.