Thermophysical properties and structural stability of some praseodymium chalcogenides
Madhu Singh, Faisal Shareef M., Atul Gour and Sadhna Singh
In present study we have investigated the high pressure phase transition, associated volume collapse, elastic and thermo-physical properties of praseodymium chalcogenides (PrX; X: S, Se, Te), using the three body interaction potential (TBIP) approach. These interactions arise due to the electron shell deformation of the overlapping ions in the crystals. The present TBIP model consists of long range Coulombic, three body interaction and the short range overlap repulsive forces operative up to next nearest neighbor ions. The praseodymium chalcogenides belong to the wide class of binary rare-earth monochalcogenides, which crystallize into NaCl structure under ambient conditions and undergo NaCl to CsCl phase transition under high pressure. The values of phase transition pressure, associated volume collapse, bulk modulus and its pressure derivative estimated by us are found to be well suited with experimental values. In view of its overall success, it can be regarded as an adequate and appropriate model suitable for high pressure studies.
Keywords: Phase transition, many body interaction, elastic properties, thermo physical properties.