Site occupancy, valence state, and spin state of Co ions in Co-doped In2O3 diluted magnetic semiconductor
Site occupancy, valence state, and spin state of Co ions in Co-doped In2O3 diluted magnetic semiconductor
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DOI：
10.1016/j.jmmm.2019.165358
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发表时间：
2019-11
影响因子：
2.7
通讯作者：
H. Kumagai;Y. Hara;K. Sato
中科院分区：
文献类型：
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作者：
H. Kumagai;Y. Hara;K. Sato
本研究旨在研究化学溶液法制备的共掺杂in2o3中Co离子的24d和8b位占有率、价态和自旋态。产品x射线粉末衍射图的Rietveld分析表明，Co 2+和Co 3+离子分别倾向于占据24 d和8 b位。x射线光电子能谱分析表明，低掺杂区（x≤0.044）以Co 2+离子为主，高掺杂区（x≥0.052）以Co 3+离子为主。磁化率测量表明，低掺杂区Co 2+的有效玻尔磁子数为~ 3.8，与高自旋（S= 3/2）态Co 2+的值一致。在Co 3+离子出现的高掺杂区，pe f减小。这些结果表明，co3 +离子处于低自旋（S= 0）或中自旋（S= 1）状态。
This study aims to investigate the 24 d and 8 b site occupancies, valence state, and spin state of Co ions in Co-doped In 2 O 3 prepared by a chemical solution method. The Rietveld analysis of X-ray powder diffraction patterns of the products revealed that Co 2+ and Co 3+ ions tend to occupy the 24 d and 8 b sites, respectively. X-ray photoelectron spectroscopy analysis indicated that the Co 2+ ions are dominant at low-doping region (x≤ 0.044) and that Co 3+ ions appear at high-doping region (x≥ 0.052). Magnetic susceptibility measurements revealed that the effective Bohr magneton number p e f f is~ 3.8 at the low-doping region, consistent with the value for Co 2+ in the high-spin (S= 3/2) state. The p e f f decreases at the high-doping region, where Co 3+ ions appear. These results indicate that the Co 3+ ions are in the low-spin (S= 0) state or intermediate-spin (S= 1) state.