Pressure-induced phase transition and electronic structure of curium pnictides: Ab initio calculations

We report an ab initio calculation of pressure-induced structural phase transition and electronic properties of the NaCl-type Cm-based pnictides namely CmX (X = N, P, As, Sb and Bi). The total energy as a function of volume is obtained by means of self-consistent tight-binding linear muffin tin orbital (TB-LMTO) method by performing spin and non-spin polarized calculation. Magnetically the CmX compounds are stable in ferromagnetic (FM) state and their crystal structure is NaCl-type at ambient condition. From the present study, we predict a structural phase transition from ferromagnetic (FM) NaCl-type (B1 phase) structure to ferromagnetic CsCl-type (B2 phase) structure for curium pnictides in the pressure range of 51.0–10.0 GPa (CmN to CmBi). The pressure-induced transition is found to be first order. The band structure and density of states (DOS) are plotted in FM-B1 phase and FM-B2 phase. Apart from this the ground-state properties like magnetic moment, lattice parameter and bulk modulus are calculated and compared with the available theoretical and experimental results.