A First Principle Study of the Pressure Dependent Elastic Properties of Monazite LaPO4

DFT based ab-initio simulations have been pertbnned to study the effect of pressure on the elastic properties of monazite LaPO4 which is a promising host material for immobilization of high level nuclear waste. The phase is found to be stable up to 30 GPa. The calculated polycrystalline bulk, shear and Young moduli show an increasing trend as a function of pressure. The ductility and anisotropy in shear modulus of the material have been found to increase with pressure; whilethe hulk modulus anisotropy decreases with pressure.