OPTICAL-SPECTRA IN (LA,Y)TIO3 - VARIATION OF MOTT-HUBBARD GAP FEATURES WITH CHANGE OF ELECTRON CORRELATION AND BAND FILLING
OPTICAL-SPECTRA IN (LA,Y)TIO3 - VARIATION OF MOTT-HUBBARD GAP FEATURES WITH CHANGE OF ELECTRON CORRELATION AND BAND FILLING
复制标题
DOI：
10.1103/physrevb.51.9581
复制
发表时间：
1995-04-15
影响因子：
3.7
通讯作者：
TOKURA, Y
中科院分区：
文献类型：
--
作者：
OKIMOTO, Y;KATSUFUJI, T;TOKURA, Y
研究了典型的Mott-Hubbard(MH)绝缘体LaTiO3和YTiO3及其固溶体LaxY1−xTiO3的光谱。MH带隙随x或当量随单电子带宽W的变化呈现临界变化。通过对快速变化的MH带隙与电子关联强度(Ũ=U/W)的外推，我们可以确定每种化合物到假设的Mott转变点(Ũc)的相对距离。还研究了LaTiO3+δ/2在标称空穴浓度δ下的能带填充关系。讨论了MH禁带的系统崩塌，以及填充控制化合物Y1−xCaxTiO3在掺杂诱导的光谱重量转移方面的类似结果。
Optical spectra have been investigated for the prototypical Mott-Hubbard (MH) insulators LaTiO 3 and YTiO 3, and their solid solutions La x Y 1− x TiO 3. The MH gap shows a critical variation with x or equivalently with the change of the one-electron bandwidth W. By an extrapolation of the rapidly varying MH gap with the electron correlation strength (Ũ= U/W), we could determine the relative distance of each compound from the hypothetical Mott transition point (U ̃ c). The band-filling dependence of the gap spectra has been also investigated for LaTiO 3+ δ/2 with the nominal hole concentration δ. The systematic collapse of the MH gap is argued, together with similar results on filling-controlled compounds Y 1− x Ca x TiO 3, in terms of doping-induced spectral weight transfer.