| Time：115/10/7 (Wed.) 14:20~16:20 Speaker：Prof.駱芳鈺(Fang-Yu Lo) 國立臺灣師範大學物理學系/Department of Physics, National Taiwan Normal University Title：Annealing and thickness effects on strain and magnetic anisotropy of samarium yttrium iron garnet thin films Abstract： Extensive research and development of materials with perpendicular magnetic anisotropy (PMA) has been prompted by the demand for higher density and faster access memory devices, such as magnetic random-access memories. In this study, we investigated the effects of film thickness and the annealing temperature on the strain and induced magnetic anisotropy of samarium-substituted yttrium iron garnet (SmYIG) films grown on (111)-oriented yttrium aluminum garnet (YAG) substrates by pulsed-laser deposition. The thickness of the thin films ranges between 30 and 120 nm, and they were annealed for 4 hours in ambient atmosphere at temperatures between 850℃ and 1050℃. All SmYIG thin films exhibit out-of-plane compressive strains, and the strain increases with increasing Sm content, increasing annealing temperature, and decreasing thickness. Both the in-plane magnetic anisotropy (IMA) and PMA are observed from the SmYIG thin films. The PMA of the SmYIG films is shown to improve with decreasing film thickness, increasing annealing temperatures, and increasing Sm content. The critical thickness for the IMA-to-PMA transition of SmYIG film is found to increase with Sm content – from smaller than 30 nm for YIG to above 120 nm for SmIG. Our work demonstrates that by adjusting the thickness, Sm content, and annealing temperature, we can modulate the strain and magnetic anisotropy of SmYIG films. Place：S101, Gongguan Campus, NTNU |
