Optical study of charge instability in CeRu2Al10 in comparison with CeOs2Al10 and CeFe2Al10

• Published in: arXiv.org 2011-08
• Main Authors: Kimura, Shin-ichi, Iizuka, Takuya, Miyazaki, Hidetoshi, Hajiri, Tetsuya, Matsunami, Masaharu, Mori, Tatsuya, Irizawa, Akinori, Muro, Yuji, Kajino, Junpei, Takabatake, Toshiro
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Charge density waves; Electronic structure; Electrons; High temperature; Hybridization; Nesting; Photoelectric emission; Stability
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1108.4815

The anisotropic electronic structure responsible for the antiferromagnetic transition in CeRu\(_2\)Al\(_{10}\) at the unusually high temperature of \(T_0\) = 28 K was studied using optical conductivity spectra, Ce 3d X-ray photoemission spectra, and band calculation. It was found that the electronic structure in the \(ac\) plane is that of a Kondo semiconductor, whereas that along the b axis has a nesting below 32 K (slightly higher than \(T_0\)). These characteristics are the same as those of CeOs\(_2\)Al\(_{10}\) [S. Kimura {\it et al.}, Phys. Rev. Lett. 106, 056404 (2011).]. The \(c\)-\(f\) hybridization intensities between the conduction and \(4f\) electrons of CeRu\(_2\)Al\(_{10}\) and CeOs\(_2\)Al\(_{10}\) are weaker than that of CeFe\(_2\)Al\(_{10}\), showing no magnetic ordering. These results suggest that the electronic structure with one-dimensional weak \(c\)-\(f\) hybridization along the b axis combined with two-dimensional strong hybridization in the \(ac\) plane causes charge-density wave (CDW) instability, and the CDW state then induces magnetic ordering.