The effect of film structure on magnetoelastic properties of thin permalloy films

It has been observed that the magnetoelastic coefficient of thin permalloy films does not only depend on the Ni: Fe ratio but also on the film structure, which was varied by varying the deposition parameters and by annealing the films. By annealing the magnetoelastic coefficient may be shifted to more positive as well as to more negative values, depending on the annealing temperature, the gas atmosphere, and the deposition parameters, especially the crucible material. Typical thin-film effects, e.g., oxidation of the film surface and the grain boundaries, impurities enclosed within the film lattice during deposition and lattice imperfections are believed to be responsible for different magnetoelastic properties at the same film composition.