The Impact of the Composition Effect on Ferromagnetic Properties of Tb2Co2Ga
The Impact of the Composition Effect on Ferromagnetic Properties of Tb2Co2Ga
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DOI：
10.3390/met9121242
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发表时间：
2019-11
期刊：
影响因子：
2.9
通讯作者：
S. Tanaka;Hirotaka Terada;N. Shirakawa;M. Tsubota;J. Kitagawa
中科院分区：
文献类型：
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作者：
S. Tanaka;Hirotaka Terada;N. Shirakawa;M. Tsubota;J. Kitagawa
通过制备11种不同起始原子组成的多晶样品，研究了Tb2Co2Ga的铁磁性能。我们发现Tb2Co2Ga在三元相图中具有均匀性范围。居里温度TC对原子组成很敏感，范围很广，在75 ~ 145 K之间。对于TC大于90k的样品，考虑到Tb和Co原子之间杂化的RKKY相互作用，最近的Tb - Tb和Tb - Co距离是决定TC的重要因素。在温度低于90k的样品中，由2个Tb和4个Co原子组成的八面体中出现了两种Co - Tb - Co角的各向异性变化。这种八面体参数的变化似乎与最低温度组（~ 75 K）样品与其他组样品在TC处交流磁化异常的形状不同有关。
The ferromagnetic properties of Tb2Co2Ga, crystallizing into an orthorhombic W2CoB2-type structure, were investigated by preparing 11 polycrystalline samples with different starting atomic compositions. We found that Tb2Co2Ga possesses a homogeneity range in the ternary phase diagram. The Curie temperature TC is sensitive to the atomic composition and ranges rather widely, i.e., from 75 to 145 K. For the samples with a TC above 90 K, the nearest Tb–Tb and the Tb–Co distances would be important factors deciding TC, considering the RKKY interaction through the hybridization between Tb and Co atoms. An anisotropic change of two kinds of Co–Tb–Co angles in the octahedron formed by two Tb and four Co atoms occurs in the samples with a TC lower than 90 K. Such a change of octahedral parameters seems to be related to a difference of shapes in the ac magnetization anomaly at TC between the samples in the lowest TC (~ 75 K) group and those in the other groups.