Temperature–pressure behavior and equation of state of praseodymium pnictides

This paper reports an analysis on the high-pressure and temperature structural phase transition of praseodymium pnictides (phosphide: PrP and arsenide: PrAs). The Realistic Interaction Potential Approach (RIPA) model has been developed and used to study the structural and elastic properties. Phase transition pressures are associated with a sudden collapse in volume. Phase transition pressures have been reported at high temperature range 0–1000 K. The phase transition pressures and associated volume collapses obtained from present potential model show a generally better agreement with available experimental data than others. The elastic constants and their pressure derivatives are also reported. The temperature and pressure behaviors of bulk modulus for the present compounds are also discussed.