Effect of pressure on mechanical and optical properties of ThO <sub>2</sub> and PuO <sub>2</sub>
Shilpa Singh, Yogesh Sonvane, Kiril A. Nekrasov, Anatoliy Ya. Kupryazhkin, P. N. Gajjar, Sanjeev K. Gupta
Abstract
Abstract We have used DFT + U with spin–orbit coupling to understand the effect of pressure on the mechanical and optical properties of ThO 2 and PuO 2 . Both the compounds are mechanically stable in a cubic and an orthorhombic structure. The cubic AnO 2 has higher elastic constants and Bader charges on each atom than the orthorhombic AnO 2 . With an increase in pressure on cubic AnO 2 , elastic modulus increases for both the structures. Bader charge on AnO 2 and magnetic moment of PuO 2 decrease with an increase in pressure for cubic structure. The static refractive index and static dielectric function are higher for PuO 2 in both the cubic and orthorhombic structures as compared to that in ThO 2 . The mechanical and optical properties drawn comply with the experimental outcomes.