The effect of pressure on the physical properties of Cu sub(3)N

The structural, optical and electronic properties of the copper nitride (Cu sub(3)N) bulk structure under pressure have been studied by performing accurate total energy calculations in the framework of density functional theory using the full-potential linearized augmented plane wave method. Perdew-Burke-Ernzerhof and modified Becke-Johnson parameterizations of the generalized gradient approximation were employed to obtain the structural and electronic properties of Cu sub(3)N. The most stable crystal structure of the Cu sub(3)N compound was found to be cubic anti-ReO sub(3) at ambient pressure. Moreover, the calculation of the enthalpy of different crystal structures of Cu sub(3)N for different pressures indicates that the anti-ReO sub(3) cubic phase undergoes a structural phase transition for pressures higher than 30 GPa. The study of the elastic constants of the anti-ReO sub(3) cubic phase confirms that Cu sub(3)N is mechanically stable under hydrostatic pressures up to 30 GPa. Moreover, with the application of pressure, the C sub(44) elastic constant, shear module and Debye temperature deviate from linear behavior at 10 GPa. An electronic study shows that there is an electronic-type phase transition from semiconductor to metal between 5 and 10 GPa and metal to semi-metal between 20 and 30 GPa applied pressures. Cu sub(3)N is an indirect band gap semiconductor with a value of 0.56 eV.