Study of gadolinium (Gd) doped epitaxial yttrium iron garnet (YIG) thin films

Abstract

The present work reports the preparation and study of epitaxial yttrium iron garnet (YIG) thin films with Gd3+ doping at yttrium site. Epitaxy of the prepared films is confirmed from the x-ray reciprocal space mapping measurements. Room temperature M-H loops measured from laser-based magneto-optical Kerr effect (MOKE) indicate the in-plane easy axis magnetization for all the films. Element specific x-ray magnetic circular dichroism (XMCD) measurements confirm the anti-parallel alignment of Gd3+ and resultant Fe3+ at room temperature in the Gd3+ doped YIG samples. Sum rule analysis indicate that the incorporation of Gd into YIG affect the exchange interaction between two iron sub-lattices and as a result lowered the Fe moment per atom at room temperature. Out of plane variation of resonance field (HR) from ferromagnetic resonance (FMR) experiments indicate the in-plane magnetization corroborating the MOKE measurements. The in-plane HR values are observed to decrease with Gd doping in YIG film from the FMR data.