Half-metallic ferromagnetism in Ga1-xCoxP (x = 0.125, 0.25, 0.75, and 1) alloys: An ab-initio study

Abstract

III-V compounds belong to one of the most used materials in the technological applications. The doping of transition metals can induce magnetic properties in III-V for the use in spintronics applications. Effect of Co doping with different concentrations (0.125, 0.25, 0.75, and 1) on the physical properties of GaP is investigated using the spin dependent density functional theory. The equilibrium structural parameters such as the lattice constant (a0), the bulk modulus (B0) and the first pressure-derivative of the bulk modulus (B’) are optimized for all these alloys. The calculations of the electronic properties for the Ga1-xCoxP alloys at their equilibrium lattice parameters disclose that all Ga0.875Co0.125P, Ga0.75Co0.25P, Ga0.25Co0.75P, and CoP alloys are complete half-metallic materials. The magnetic properties show that the total magnetic moment for all Ga0.875Co0.125P, Ga0.75Co0.25P, Ga0.25Co0.75P, and CoP alloys has integer value. The p-d hybridization reduces the atomic magnetic moment of Co atom from its free space charge value of 2μB and creates weak local magnetic moments on the nonmagnetic Ga and P sites. Furthermore, the s(p)-d exchange coupling constants N0α and N0β constants are computed to understand role of exchange splitting process in conduction and valence bands. The high spin polarization and originating the ferromagnetism in GaP by the doping of Co can be valuable systems for the use in spin based applications in various electronic devices.