Effects of second order surface anisotropy in YIG sputtered onto GGG (100) oriented substrate*

In this work, we produced Y₃Fe₅O₁₂ textured films, with thicknesses between 50 nm and 500 nm, onto (100) GdGaO by magnetron sputtering and post annealing, and investigated the first and second order surface and cubic anisotropy constants using the ferromagnetic resonance technique. The surface anisotropy constants exhibited different behaviors with film thickness, with the first order presenting the usual inverse of ferromagnetic layer thickness. Besides this inverse of thickness behavior, the second order also came up with a constant value. In the frame of spin reorientation transition phenomenon, we evaluated volume and surface contribution to the surface anisotropy. Although the second order cubic anisotropy constant is one order of magnitude stronger than the first order, they did not show any explicit thickness dependence. As an important finding of this work, in order to correctly characterize the magnetic properties of the YIG films, it is essential to measure both, the out-of-plane and in-plane angular dependence of the FMR resonance field.