Structural and magnetic characteristics of yttrium iron garnet (YIG, Ce : YIG) films prepared by RF magnetron sputter techniques

Abstract

The effects of deposition parameters and post-deposition heat-treatment on the structural and magnetic characteristics of (Ce:) yttrium iron garnet (YIG) films, prepared by RF magnetron sputter techniques, have been investigated. The Ce ions of the Ce : YIG films are composed of Ce 3+ and Ce 4+, and the fraction of the Ce 3+ in the films is at its maximum when the oxygen fraction in sputter gas (Ar+O 2) is 10%. The variation of the chemical stoichiometry as well as the oxidation state of the Ce ions with the oxygen fraction in sputter gas is discussed with the structural and magnetic features of the films. With raising the temperature of post-deposition heat-treatment from 900°C to 1100°C, the surface roughness of the films on gadolinium gallium garnet substrates increases, but the coercive force as well as the ferromagnetic resonance linewidth decreases.