Influence of a thermal environment on the deflection of magnetostrictive thin films

The primary application areas of magnetostrictive thin films are in the field of micro-electro-mechanical systems. Devices which use the actuation capability of thin films put to advantage the induced mechanical deformations in them upon being subjected to a magnetic field. In this study, experiments are conducted, in a thermal environment, on Tb–Dy–Fe thin film samples to determine their characteristic magnetization curves. The thin films are subjected to a periodically varying magnetic field of ∼ ± 0.7 T, in a thermally controlled environment, and the deflections at the tip are measured at elevated temperatures 50, 75 and 100∘C. An analytical model constructed from the theories of elasticity, considering transversely isotropic material properties of both the film and the substrate layers, has been proposed to predict the deflections. The study has been extended to predict the tip deflections numerically (Finite Element Method) using COMSOL Multiphysics.