Magnetic and magneto-optical properties of Ni–Ge layered films

Magnetic and magneto-optical properties of layered Ge–Ni–Ge–Ni–Ge films have been investigated with the morphology of the film surface being studied also. It is shown that the films reproduce roughness of the glass-substrate surface which is similar to the grains 2–4 nm high and 100–400 nm long in any direction within the film plane. Thermal treatment results in a decrease of the grains height and their broadening. Non-monotonous change of the Faraday rotation (FR) value due to thermal treatment has been revealed. The inverse linear FR value dependence on the intermediate Ge layer thickness has been obtained. The exchange bias effect is observed at temperatures lower than approximately 50 K which was ascribed to the formation of the complex composition interface due to the Ge and Ni mutual diffusion.