磁控溅射参数对SrTiO_3基片上沉积YIG薄膜微观结构和磁性能的影响

Micro-structural and magnetic characteristics of YIG thin film prepared on SrTiO_3 substrates by RF-magnetron sputtering

采用射频磁控溅射法在SrTiO_3衬底上制备YIG薄膜,基于薄膜的成核理论研究溅射参数对薄膜结晶性、表面形貌和磁性的影响。结果表明,在其他溅射参数不变的情况下,薄膜的厚度随溅射时间成正比增长;在衬底温度为500℃、溅射气压为1Pa时,YIG薄膜表面较致密,晶粒大小均匀;沉积薄膜的化学组分受氧分压的影响较大,与靶材成分相比有一定偏差。溅射气体为纯氩气时,YIG薄膜的化学组分与靶材化学计量比接近,制备的YIG薄膜中存在一定量的Fe2+和氧空位;当退火温度为750℃时,在氧气中热处理40 min,形成纯的YIG相,饱和磁化强度为134emu/cm3。

YIG thin films were deposited on SrTiO3 substrate by an RF-magnetron sputtering. The crystallization, surface morphology and magnetic property of the thin films were investigated based on the sputtering parameters. The results showed that the film thickness increases in a linear relationship with sputtering time. The YIG film with compact surface and uniform crystalline grains was obtained at deposition temperature of 500 ℃ and sputtering pressure of 1 Pa. The chemical stoichiometry compared with the target material composition has a certain deviation which is relative to the oxygen fraction in sputtering gas. It is shown that O2/Ar ratio of 0：10 is the best condition to form a stoichiometrie YIG film. There are Fe^2＋ and oxygen vacancies in the deposited film. Pure phase YIG thin film was obtained with high saturation magnetization （Mn） of 134 emu/cm^3 after heat treatment in oxygen atmosphere at 750 ℃ for 40 min.