磁気光学カー効果測定における酸化保護膜の利用

Abstract

In measuring optical constants relating to the reflection phenomenon, the presence of oxidation layer at the surface makes unclear the real material properties. In this paper, the influence of an oxidation protection layer on the reflection constant of the material is calculated numerically as a function of the protection layer thickness for a film consisting of (Si)_3N_4/Gd-Co. The saturation polar Kerr rotation of Dy-Co amorphous films with and without the oxidation protection layer of 10 [nm] thick, which are prepared at the same time, was measured immediately after removing the film from the deposition chamber. It is confirmed that the difference in the Kerr rotation is less than 0.01 [deg] for a wavelength range of 600-1,000 [nm] and less than 0.02 [deg] for 400-600 [nm]. The Kerr rotation of a film with the protection layer was confirmed to be hardly changed over 100 days when the film was kept at room temperature in a dry atmosphere.