Structural, electronic and magnetic properties of quaternary half-metallic Heusler alloy CoFeCrAl

Abstract

We have investigated the structural, electronic and magnetic properties in quaternary CoFeCrAl Heusler alloy. Rietveld refinement and Mössbauer spectroscopy of samples quenched from 973 K show absence of the A2 phase and presence of a highly ordered B2-type structure. Full-potential linearized augmented plane wave calculations using the experimental lattice constant show that there is an energy gap of 0.41 eV around the Fermi level in the bands for minority spin electrons. Partial substitution of Co by Fe in Co2CrAl thus brings excellent structural ordering while retaining the high Curie temperature, spontaneous magnetization and half-metallicity necessary for application as spin valves. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.