Simultaneous measurements of the magnetostrictive coefficient, Young's modulus, and Poisson ratio of thin films

A method, which determines simultaneously the magnetostrictive coefficient, Young's modulus, and Poisson ratio of a thin film utilizing the minimizati on of the total elastic energy of a cantilever film-substrate system, is su ggested. An inaccuracy for the magnetostrictive coefficient, caused by assu ming the elastic properties of the film as those of the corresponding bulk material, could be avoided and only a single elastic isotropic substrate is employed in the present method. The experimental data of an Fe-based amorp hous thin film were analyzed by using the model. The calculated dependence of the magnetostrictive coefficient on the external magnetic field was comp ared with the experiment, and the discrepancy between both results were exp lained. The elastic properties of the film were also obtained. (C) 2001 Ame rican Institute of Physics.