Anisotropic Thermopower of the Antiferromagnetic Kondo Semiconductor CeOs2Al10 Doped with 5d Electrons and Holes

作者：Yamada Yoshihiro^*; Kawabata Jo; Onimaru Takahiro; Takabatake Toshiro

来源：Journal of the Physical Society of Japan, 2015, 84(8): 084705.

DOI：10.7566/JPSJ.84.084705

The thermopower S and electrical resistivity rho of Ce(Os1-xIrx)(2)Al-10 and Ce(Os1-yRey)(2)Al-10 single crystals have been measured to understand the properties of the unusual antiferromagnetic order at T-N = 28.5 K in the orthorhombic Kondo semiconductor CeOs2Al10. Opening of a gap in the hybridized band of CeOs2Al10 manifests in the activation-type increase of rho(T) along the principal axes on cooling below 60 K, whereby S-a(T) and S-c(T) exhibit shallow minima. Below T-N, S-a(T) and S-c(T) jump by a few mu V/K, whereas S-b(T) sharply decreases from 30 to -7 mu V/K, suggesting a loss of a part of the Fermi surface of the hybridized band. The large maximum in S-b(T) between 100 and 40K is suddenly suppressed by doping 5d electrons and holes at a few % level. With further doping of 5d electrons and holes, respectively, the hybridization gap behaviors of both S(T) and rho(T) change to those of metallic Kondo system and valence fluctuating system.

• 出版日期2015-8-15