Zhang Yuanjing, Yang Qinghui, Liu Yingli, Hu Aimin, Zhang Ding, Li Han, Yu Jingyan, Huang Jiantao, Lu Yongcheng, Zhang Lei, Xue Qiang, Li Yilei, Jin Lichuan, Wen Qiye, Zhang Huaiwu
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, 610054 Chengdu, People's Republic of China.
Acta Crystallogr B Struct Sci Cryst Eng Mater. 2023 Apr 1;79(Pt 2):157-163. doi: 10.1107/S2052520623000483. Epub 2023 Mar 2.
Ultra-thin rare earth iron garnet (RIG) films with a narrow ferromagnetic resonance (FMR) line width and a low damping factor have attracted a great deal of attention for microwave and spintronic applications. In this work, 200 nm Y(GaAlFe)O garnet (GaAl-YIG) films were prepared on gadolinium gallium garnet (GGG) substrates by liquid-phase epitaxy (LPE) with low saturation magnetization. The microstructural properties, chemical composition, and magnetostatic and dynamic magnetization characteristics of the films are discussed in detail. According to the structural analysis, these films exhibit a low surface roughness of less than 0.5 nm. The GaAl-YIG films show an obvious temperature dependence of lattice parameter and strain state, and the film's parameter is perfectly matched with that of the GGG substrate at 810°C. There is a clear variation in the Pb level, which brings about a gradual enhancement of the coercivity and a diminution of the squareness ratio of magnetic hysteresis loops as the growth temperature is reduced. Slight changes in surface roughness, strain condition and content of Pb induce the FMR line width and damping factor to vary on a small scale. The line width is less than 10.17 Oe at 12 GHz and the damping factor is of the order of 10. All these properties demonstrate that these ultra-thin GaAl-YIG films are of benefit for the development of devices operated at lower frequencies and in lower fields.
具有窄铁磁共振（FMR）线宽和低阻尼因子的超薄稀土铁石榴石（RIG）薄膜在微波和自旋电子学应用中引起了广泛关注。在这项工作中，通过液相外延（LPE）在钆镓石榴石（GGG）衬底上制备了具有低饱和磁化强度的200 nm Y（GaAlFe）O石榴石（GaAl-YIG）薄膜。详细讨论了薄膜的微观结构特性、化学成分以及静磁和动态磁化特性。根据结构分析，这些薄膜的表面粗糙度低于0.5 nm。GaAl-YIG薄膜的晶格参数和应变状态表现出明显的温度依赖性，并且在810°C时薄膜的参数与GGG衬底的参数完美匹配。Pb含量存在明显变化，随着生长温度降低，这导致矫顽力逐渐增强，磁滞回线的矩形比减小。表面粗糙度、应变条件和Pb含量的微小变化会使FMR线宽和阻尼因子在小范围内变化。在12 GHz时线宽小于10.17 Oe，阻尼因子约为10。所有这些特性表明，这些超薄GaAl-YIG薄膜有利于开发在较低频率和较低磁场下工作的器件。
