Annealing kinetics of thin Permalloy films.

Low-temperature (250-310C) annealing was found to cause a large decrease in the resistivity of RF sputter-deposited thin (less than or equal to 500A) Permalloy films. A transmission electron microscope was used to investigate a probable microstructural change occurring during the annealing. It was found that the low-temperature annealing induced considerable grain growth in these films. Furthermore, an electron diffraction analysis has shown that this grain growth was accompanied by the formation of the ordered phase (Ni(3)Fe). The use of darkfield imaging revealed that the small ordered region appears to be formed around the disordered regions via a grain-boundary diffusion mechanism.