Perpendicular Magnetic Anisotropy of Co2FeAl/Pt Multilayers for Spintronic Devices

We report on the experimental realization of perpendicular magnetic anisotropy in Co2FeAl/Pt multilayers, which were prepared on Pt buffered MgO(001) substrates by magnetron sputtering. It was found that the perpendicular magnetic anisotropy is related to the number of periods N of the multilayers and also the thickness of Co2FeAl. The perpendicular-anisotropy energy density Ku is estimated to be 1.45×106 erg/cm3 at room temperature, which is comparable to that of the Co/(Pd,Pt) multilayers. This suggests that Co2FeAl/Pt system presented here will be a good candidate for use as the highly spin polarized ferromagnetic electrodes in MgO-based tunnel junctions with perpendicular magnetization.