Ti 3d orbital change across metal-insulator transition in Ti2O3:: Polarization-dependent soft X-ray absorption spectroscopy at Ti 2p edge
Ti 3d orbital change across metal-insulator transition in Ti2O3:: Polarization-dependent soft X-ray absorption spectroscopy at Ti 2p edge
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DOI：
10.1143/jpsj.75.053702
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发表时间：
2006-05-01
影响因子：
1.7
通讯作者：
Taniguchi, Masaki
中科院分区：
文献类型：
--
作者：
Sato, Hitoshi;Tanaka, Arata;Taniguchi, Masaki
利用极化相关软X射线吸收谱（XAS）研究了Ti_2O_3在金属-绝缘体转变（MIT）过程中的3d电子结构. XAS光谱显示出显著的线性二向色性（LD）之间的入射光的偏振矢量平行和垂直于钛离子对沿着c轴。与300 K时的绝缘相相比，520 K时金属相的LD强度显著降低，表明a（1g）和e（g）（pi）轨道占据发生了较大的变化.结果与最近的理论定性一致，其中MIT是由于在Ti对沿着c轴的3d电子配置的变化驱动的变化在t（2g）能级分裂相对于现场交换相互作用。
The Ti 3d electronic structure of Ti2O3 across metal-insulator transition (MIT) has been investigated by means of polarization-dependent soft X-ray absorption spectroscopy (XAS) at the Ti 2p edge. The XAS spectra exhibit a remarkable linear dichroism (LD) between the polarization vectors of the incident light parallel and perpendicular to the Ti ion pair along the c-axis. LD intensity is significantly reduced at 520 K in the metallic phase in comparison with that at 300 K in the insulating phase, indicating a large change in a(1g) and e(g)(pi) orbital occupations. The results are qualitatively consistent with a recent theory, where the MIT is due to the change of the 3d electronic configuration in the Ti pair along the c-axis driven by a change in the t(2g) level splitting relative to the on-site exchange interaction.