Magnetic properties of magnetostrictive films on piezoelectric single crystal substrates

The magnetic properties, especially magnetic softness and anisotropy, of highly magnetostrictive FeSiB amorphous films deposited on glass, silicon, Quartz, and LiNbO3 substrates have been investigated. Although the films were deposited and annealed with the same process condition, there were quite large differences between the magnetic properties with variation of substrate. The prime factor defining the magnetic properties was defined with difference between the thermal expansions of film and substrate. When the film were deposited on the substrate with larger thermal expansion compared to the film, the soft magnetic properties became worse due to perpendicular anisotropy, which was coursed by compressive stress. For example, the coercive force of the film on LiNbO3 substrate was about 30 Oe, while the coercive force of the film on silicon substrate was 0.3 Oe