First principles study of structural, electronic, mechanical and magnetic properties of actinide nitrides AnN (An = U, Np and Pu)

Abstract The electronic, structural, mechanical and magnetic properties of Actinide nitrides AnN (An = U, Np and Pu) are investigated in three cubic phases, namely, NaCl (B1), CsCl (B2) and zinc blende (B3). At normal pressure, UN is stable in antiferromagnetic state while the other two nitrides are stable in the ferromagnetic state with NaCl (B1) structure. A pressure induced structural phase transition from B1 to B3 phase is predicted in these nitrides. The electronic structure reveals that these nitrides are metallic in nature. The magnetic phase transition from antiferromagnetic to non-magnetic state is observed in UN at a pressure of 127 GPa while ferromagnetic to non-magnetic state is observed in NpN and PuN at the pressures of 67 GPa and 102.3 GPa respectively. The computed structural parameters, bulk modulus density of states and charge density distributions are compared with experimental and other theoretical calculations.