X-ray absorption spectroscopic study of mixed valence systems EuCu2Si2, YbCu2Si2 and Sm4Bi3
X-ray absorption spectroscopic study of mixed valence systems EuCu2Si2, YbCu2Si2 and Sm4Bi3
复制标题
混合价系 EuCu2Si2、YbCu2Si2 和 Sm4Bi3 的 X 射线吸收光谱研究
DOI：
10.1016/0038-1098(80)90939-4
复制
发表时间：
1980
影响因子：
2.1
通讯作者：
R. Vijayaraghavan
中科院分区：
文献类型：
--
作者：
T. Hatwar;R. M. Nayak;B. D. Padalia;M. N. Ghatikar;E. Sampathkumaran;L. C. Gupta;R. Vijayaraghavan
用X射线吸收光谱法测定了EuCu/sub 2/Si/sub 2/，YbCu/sub 2/Si/sub 2/和Sm/sub 4/Bi/sub 3/中稀土离子的价态。在每种情况下，已经观察到对应于相应稀土离子的两个不同价态的两个吸收峰。EuCu/sub 2/Si/sub 2/的低温（77 K）研究表明，与室温（300 K）下记录的吸收峰相比，吸收峰的相对强度发生了明显的变化。从相对强度的变化推断，与Eu/sup 3 +/相比，Eu/sup 2 +/在EuCu/sub 2/Si/sub 2/中的布居在液氮温度下减少。从这些结果得出的结论与其他人使用不同的实验技术报道的一致。在Sm/sub 4/Bi/sub 3/中，Sm/sup 2 +/和Sm/sup 3 +/以3：1的比例存在。
X-ray absorption spectroscopy technique is employed to determine the valence of the rare earth ions in EuCu/sub 2/Si/sub 2/, YbCu/sub 2/Si/sub 2/ and Sm/sub 4/Bi/sub 3/. In each case, two absorption peaks corresponding to two different valence states of respective rare earth ions have been observed. Low temperature (77 K) study of EuCu/sub 2/Si/sub 2/ indicates distinct change in the relative intensities of the absorbtion peaks compared to those registered at room temperature (300 K). It is inferred from the change in the relative intensities that the population of Eu/sup 2 +/ in EuCu/sub 2/Si/sub 2/ decreases at liquid nitrogen temperature compared to Eu/sup 3 +/. Conclusions drawn from these results agree well with those reported by others using different experimental techniques. In Sm/sub 4/Bi/sub 3/, Sm/sup 2 +/ and Sm/sup 3 +/ are found to occur in the ratio of 3:1.