Structural, electronic and magnetic properties of full-Heusler alloy Co2CrAl

Abstract

The first-principle calculations combined with the full-potential linearized augmented plane wave method with the help of density functional theory (DFT) implemented in WIEN2k within the Perdew-Burke-Ernzerhof of generalized gradient approximations (GGA-PBE), LSDA, GGA+U (local spin density approximation (LSDA)+U) are used to investigate the structural, electronic and magnetic properties of full-Heusler alloy Co2CrAl. We add the parameter, “U” to GGA and LSDA approximations to improve certain physical parameters. We found that the structure Fm-3m is stable and we also determined the parameters of the equilibrium lattice using the optimizing method. The lattice constant, bulk modulo, energy gap, spin polarization and density of have been calculated. The LSDA, LSDA+U, GGA and GGA+U approximations are used to calculate the density of state and band structure analysis together with spin magnetic moments. It is found that Co2CrAl has a half metallic character for a wide range of lattice parameters. The exchange energy calculated confirms that the ground state ferromagnetic (FM) is more stable than the non-magnetic (NM) states of L21 phase. The magnetic moment of Co and Cr is obtained in Co2CrAl using LSDA+U and GGA+U approaches. The thermal magnetization, magnetic entropy change, adiabatic temperature change and relative cooling power are obtained via Monte Carlo simulation using the value of exchange couplings found by Ab initio calculations. The curie temperature has been established. The half metallic is one of the key properties of magnetic materials for the application of spintronics devices and magnetic refrigeration.