Abstract
Co2CrAl (x = 0) films were found to form a B2 structure, and when Fe was substituted for Cr (x = 0.4−0.6), the films crystallized B2+A2 structures, while an A2 structure was stable in the case of Co2FeAl (x = 1) films deposited on thermally oxidized Si substrates at room temperature. The magnetic moments of the films containing Fe tended to increase with increasing x, while those of the films containing Cr were far from the values calculated with an assumption of the L21 structure ordering.
Spin-valve-type tunneling junctions with a Co2(Cr1-xFex) Al film were also fabricated, which demonstrated large tunneling magnetoresistance of 19.1% (x= 0.4) at room temperature and 27.2% at 5 K in spite of atomic site disorder.