Morphology, Crystal Structure and Ferromagnetic Resonance Properties of Submicron-Thick Yttrium Iron Garnet Films Prepared by Pulsed Laser Deposition

Submicron-thick yttrium iron garnet films were grown on a gadolinium gallium garnet substrate by pulsed laser deposition. The morphology and crystal structure results show that the submicron-thick film has a flat surface, low surface roughness of ∼ 0.5 ± 0.05 nm and good epitaxy with the (444) plane. Magnetic hysteresis loops also indicate that the submicron-thick film has great soft magnetic properties. However, the ferromagnetic resonance (FMR) spectrum shows that the submicron-thick film has multiple resonance peaks. The angular dependence of the FMR response of the 10-nm-thick, 100-nm-thick and 525-nm-thick films shows that peaks 1 (at low field) and 2 (at high field) observed in the 525-nm-thick film spectrum originate from the internal layer and the outer layer of the films, respectively. Lastly, the angular dependence of the FMR linewidth shows that the lowest FMR linewidth occurred at an angle between the direction of the static field and film normal of 50°.