Doping Effects on the Electronic Structure of an Anisotropic Kondo Semiconductor CeOs$_2$Al$_{10}$: An Optical Study with Re and Ir Substitution

Shin-ichi Kimura; Hitoshi Takao; Jo Kawabata; Yoshihiro Yamada; Toshiro Takabatake

doi:10.7566/JPSJ.85.123705

paper

Doping Effects on the Electronic Structure of an Anisotropic Kondo Semiconductor CeOs $_{2}$ Al $_{10}$ : An Optical Study with Re and Ir Substitution

arXiv:1610.05880 · doi:10.7566/JPSJ.85.123705

Abstract

An anisotropic Kondo semiconductor CeOs $_{2}$ Al $_{10}$ exhibits an unusual antiferromagnetic order at rather high transition temperature $T_{0}$ of 28.5 K. Two possible origins of the magnetic order have been proposed so far, one is the Kondo coupling of the hybridization between the conduction ( $c$ ) and the $4 f$ states and the other is the charge-density wave/charge ordering along the orthorhombic $b$ axis. To clarify the origin of the magnetic order, we have investigated the electronic structure of hole- and electron-doped CeOs $_{2}$ Al $_{10}$ [Ce(Os $_{1 - y}$ Re $_{y}$ ) $_{2}$ Al $_{10}$ and Ce(Os $_{1 - x}$ Ir $_{x}$ ) $_{2}$ Al $_{10}$ , respectively] by using optical conductivity spectra along the $b$ axis. The intensity of the $c$ - $f$ hybridization gap at $ℏ ω \sim 50$ meV continuously decreases from $y = 0.10$ to $x = 0.12$ via $x = y = 0$ . The intensity of the charge excitation observed at $ℏ ω \sim 20$ meV has the maximum at $x = y = 0$ as similar with the doping dependence of $T_{0}$ . The fact that the charge excitation is strongly related to the magnetic order strengthens the possibility of the charge density wave/charge ordering as the origin of the magnetic order.

arXiv comment5 pages, 3 figures, to be published in J. Phys. Soc. Jpn

Doping Effects on the Electronic Structure of an Anisotropic Kondo Semiconductor CeOs2​Al10​: An Optical Study with Re and Ir Substitution

Abstract

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Doping Effects on the Electronic Structure of an Anisotropic Kondo Semiconductor CeOs $_{2}$ Al $_{10}$ : An Optical Study with Re and Ir Substitution