Optical Observation of Energy Gap of R3Au3Sb4 (R=La, Ce)
Optical Observation of Energy Gap of R3Au3Sb4 (R=La, Ce)
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R3Au3Sb4 (R=La, Ce) 能隙的光学观察
DOI：
10.1143/jpsj.62.4174
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
M. Ikezawa
中科院分区：
文献类型：
--
作者：
S. Kimura;Yasuhiko Sato;F. Arai;K. Katoh;M. Kasaya;M. Ikezawa
测量了R3 Au 3 Sb 4（R=La，Ce）多晶在6，78和2 97 K下，光子能量范围为5 ~ 40 eV的反射光谱.观察到两种材料的窄能隙。在La 3 Au 3 Sb 4中，可以看出约150 meV的能隙是间接能隙.在0.7 eV附近观察到由于直接和允许跃迁引起的吸收。这些结果与计算的能带结构一致。在Ce 3 Au 3 Sb 4中，可以看出约70 meV的能隙是直接能隙.差距被认为由被占用的4f态和未被占用的5d态组成。
Reflectivity spectra of R 3 Au 3 Sb 4 (R=La, Ce) polycrystals were measured in the photon energy range from 5 meV to 40 eV at 6, 78 and 297 K. A narrow energy gap was observed for both materials. In La 3 Au 3 Sb 4 , it was seen that the energy gap of about 150 meV is an indirect one. The absorption due to the direct and allowed transition was observed around 0.7 eV. These results are consistent with the calculated band structure. In Ce 3 Au 3 Sb 4 , it was seen that the energy gap of about 70 meV is a direct one. The gap is considered to consist of the occupied 4 f state and the unoccupied 5 d state.