Influence of substrate temperature driven magnetic anisotropy on the magnetostrictive behavior of Tb Fe Co thin films

Abstract Tb Fe Co thin films were grown at different substrate temperatures on Si 〈1 0 0〉 substrates to engineer their structure, microstructure, magnetic anisotropy and magnetostriction. Structural studies showed an amorphous structure for the as-deposited film. However, films deposited at higher substrate temperatures exhibited formation of Tb 2 (Fe,Co) 17 and Fe Co phases. Magnetization studies displayed presence of in-plane magnetic anisotropy for all the films. In addition to this, strong out-of-plane magnetic anisotropy co-existing with in-plane component has been observed for the film grown at 400 °C. These observations were further confirmed by the magnetic microscopy studies which showed strong magnetic phase contrast for the film processed at 400 °C. Consequently, the magnetostriction calculated from tip deflection measurements was found to be very small for this film. A maximum magnetostriction of about 300 ppm has been realized for the film grown at 550 °C owing to the presence of in-plane magnetic anisotropy, enhancement in crystallization and relaxation of stresses.