Optimization of the /spl Delta/E-effect in thin films and multilayers by magnetic field annealing

Summary form only given. The /spl Delta/E-effect of amorphous thin films (e.g. Fe-Co-B-Si, TbFe) and multilayers (e.g. TbFe/FeCo, TbFe/FeCoBSi) deposited on Si and glass substrates using magnetron sputtering has been investigated. Thin films with a high /spl Delta/E-effect are interesting for microsensor applications. Nevertheless, most of the work in the literature deals with the /spl Delta/E-effect in amorphous ribbons, much less is reported on thin films. This may be due to the problems in obtaining stress free films. For films with a high /spl Delta/E-effect materials are needed which combine high magnetostriction and low anisotropy. This means that the different anisotropy contributions in the films must be controlled a well as the stress state of the films in order to optimise the effect. Influences of substrates, sputtering parameters and annealing conditions (with and without magnetic field in different configurations) on the effect are discussed. The authors show a typical measurement of the /spl Delta/E-effect in a field-annealed amorphous (Fe/sub 90/Co/sub 10/)/sub 90/Si/sub 12/B/sub 10/ film and compare the as deposited with an annealed film. The effect size is about 30% assuming the Young´s modulus of the film as 150 GPa. Measurements are based on the vibrating reed (mechanical resonance) method in parallel and perpendicular configuration. The results are discussed by comparing the /spl Delta/E-measurements with magnetostriction and magnetization as well as with data from literature.