Abstract Indium-substituted yttrium iron garnet samples, Y3Fe5−xInxO12 (x = 0–0.7, step 0.1), were prepared using a citrate solgel method. Synchrotron X-ray diffraction (SXRD) measurements combined with the Rietveld refinement technique were used to investigate the crystallization, structure parameters and lattice distortion in the samples. Magnetization and Curie temperature of the samples were measured with the SQUID and VSM equipments. The non-magnetic indium ions were found to reside at the octahedral sites, leading to an increase of the total magnetization and a decrease in the Curie temperature. Molecular field coefficients Naa, Ndd and Nad were determined by fitting the experimental thermomagnetization curves in the framework of a two-sublattice ferrimagnetic model. The stiffness constant of the spin waves, D, in these samples was calculated based on the exchange interaction constants, Jij, and its temperature dependence was derived for the sublattice magetizations. The calculated results for D(T) are in good agreement with the experimentally measured data and are significantly large around room temperature.

中文翻译：

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取代钇铁石榴石的磁相互作用和自旋波刚度常数

摘要 铟取代的钇铁石榴石样品 Y3Fe5-xInxO12（x = 0-0.7，步骤 0.1）使用柠檬酸盐溶胶凝胶法制备。同步加速器 X 射线衍射 (SXRD) 测量与 Rietveld 精修技术相结合，用于研究样品的结晶、结构参数和晶格畸变。样品的磁化和居里温度用 SQUID 和 VSM 设备测量。发现非磁性铟离子驻留在八面体位置，导致总磁化强度增加和居里温度降低。分子场系数 Naa、Ndd 和 Nad 通过在两个亚晶格亚铁磁模型的框架中拟合实验热磁化曲线来确定。自旋波的刚度常数，D，在这些样品中，基于交换相互作用常数 Jij 计算出其温度依赖性，用于亚晶格磁化。D(T) 的计算结果与实验测量数据非常吻合，并且在室温附近明显大。