In this work, preferential site occupation in La–Co-substituted barium hexaferrites was systematically investigated by micro-Raman and Mössbauer spectroscopy. The effect of substitution on the magnetic properties was studied by vibrating sample magnetometer. Raman studies showed redshift in $2a$ , $2b$ , and $4f_{2}$ sites with Co and La substitution. The decrease in isomer shift and the relative sub-spectral area suggest that Co²⁺ ions preferably occupy $2a$ and $2b$ sites for Co-substituted sample. For La–Co substitution, Co also occupies $4f_{2}$ site as evidenced by the reduction in hyperfine field. Anisotropic field calculated by the law of approaching saturation was found to decrease with substitution. Curie temperature showed a strong dependence on La and Co substitution.

中文翻译：

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La-Co 取代的六铁酸钡的位点占据和磁性研究

在这项工作中，通过显微拉曼和穆斯堡尔光谱系统地研究了 La-Co 取代的六铁酸钡中的优先位点占据。通过振动样品磁强计研究了置换对磁性能的影响。拉曼研究显示红移 $2a$ , $2b$ ， 和 $4f_{2}$ Co 和 La 取代的位点。异构体位移和相对亚谱面积的减少表明 Co ²⁺离子优先占据 $2a$ 和 $2b$ 共取代样品的位点。对于 La-Co 置换，Co 也占据 $4f_{2}$ 超精细场的减少证明了这一点。发现由接近饱和定律计算的各向异性场随着置换而减小。居里温度对 La 和 Co 取代有很强的依赖性。