Interface and bulk magnetism of Co2Cr0.6Fe0.4Al and Co2CrAl thin films

The interface and bulk magnetic properties of epitaxial thin films of the Heusler compounds Co2Cr0.6Fe0.4Al/Mg/AlOx and CoCr2Al/Mg/AlOx are investigated. We compare the magnetization measured by x-ray magnetic circular dichroism experiments in surface sensitive total electron yield mode (information depth of 2–3 nm) and in bulk sensitive transmission mode. The pronounced temperature dependence of the magnetoresistance of tunneling junctions with Heusler electrodes, which is often related to weakened interface magnetism, is discussed. Evidence is given that this explanation does not apply to the compounds investigated here.