Magneto-optical properties of amorphous alloy films

Abstract

The study of magneto-optical as well as transport and magnetic propertics of ferrimagnetic amorphous films of Gd-Fe is extended by comparing them to single magnetic component alloys such as Fe-Bi and Gd-Au. We show that the Faraday rotation θ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</inf> can be expressed as an additive property in terms of the Kundt's constant K, where θ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</inf> = K(Fe)4πM(Fe) + K(Gd)4πM(Gd). Values of K(Fe) ≈ 20 degs/cm-G and K(Gd) ≈ -9 degs/cm-G are found. In addition the relation θ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</inf> = 2nθ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</inf> /λ where θ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</inf> is the Hall angle gives the index of refraction n for wave length λ, in reasonable agreement with measured values of n for Gd-Fe alloys obtained by other techniques.