Magnetic and structural properties of Co-rich CoFeZr amorphous thin films

The various structural and magnetic properties of amorphous Co89-xFexZr11 thin films: prepared by ion beam sputtering, were studied as a function of Fe content for 0 less than or equal to x less than or equal to 26. Whatever the amount of Fe a well-defined amorphous structure is formed, which remains stable for annealing up to 300 degrees C The substitution of Fe for Co allows the saturation magnetization to be increased. It favors also the formation of a perpendicular anisotropy field H-p which develops aside the in-plane uniaxial field H-k. H-k was induced by the DC magnetic field applied parallel to the film plane during deposition, One can suppress H-p and adjust H-k to a desired Value by an adequate field annealing process, as shown by the investigations of the domain structure and study of the hysteresis loop, which revealed also that the films are very soft ferromagnets. A well-defined standing spin wave (SSW) spectra was detected using FMR measurements, which confirmed as well the high magnetic softness of the films. H-p arises at the origin of a weak stripe domain structure and a peculiar high-frequency spectra which transforms into a classical one as H-p is suppressed. The interest for practical applications of Fe substitution in a-CoZr films is pointed out. (C) 1999 Elsevier Science B.V. All rights reserved.