We investigated the structural and magnetic properties of Co2MnAl thin films with Cr buffer layers, and the tunnel magnetoresistance (TMR) effect of junctions using Co2MnAl Heusler alloy. The saturation magnetization of Co2MnAl film deposited at 350°C was 711 emu/cm3 which was almost the same as that reported for bulk. The maximum TMR ratio of the junctions was 12% at room temperature and 26% at 25K. TMR ratio increased to 17% at room temperature after annealing at 200°C for one hour.
