Characterizing the Magneto-optic Properties of Amorphous Rare Earth - Transition Metal Thin Films

Abstract

AbstractThe amorphous rare earth - transition metal (RE-TM) thin film alloys and nanolayered materials exhibit numerous properties advantageous for optical recording, including perpendicular anisotropy, high coercivity and low magnetization at room temperature, low noise, and easily adjustable Curie and compensation points. As a result these materials have been employed in all commercial magneto-optic (MO) media. On the other hand, the MO effect of these materials is relatively small and tends to decrease with decreasing wavelength. It is important to understand the useful limits of these materials in MO media, and to determine if their MO figure of merit can be substantially increased through appropriate doping or nanolayering. In this paper we discuss experimental techniques for measuring MO properties, a theoretical approach for analyzing the data and designing optical thin film stacks, and results for a variety of RE-TM thin film materials.