Magnetic and structural properties of nonequilibrium Fe-Cu and Fe-Ag alloys produced by vapor quenching

Fe-rich Fe-Cu and Fe-Ag alloy films were sputter-deposited on water-cooled substrates under Ar gas at pressures, PAr, between 1.5 and 80 mTorr. X-ray diffraction, scanning electron micrograph (SEM), Mössbauer effect and magnetization measurements were made on these films. With the increase in PAr, the single bcc phase is extended for Fe-Ag alloys and is almost independent of PArfor Fe-Cu alloys. The alloy films sputter-deposited under low PArhave a fibrous structure in the SEM image and show an in-plane magnetic anisotropy in the Mössbauer spectrum, while those under high PArhave a columnar structure in the SEM image and show a perpendicular magnetic anisotropy in the Mössbauer spectrum. Especially in bcc and fcc mixed Fe-Cu alloys sputter-deposited under high PAr, the magnetization curve perpendicular to the film plane is almost the same as that parallel to the film plane.