The optical conductivity spectra were obtained in the single crystal with ab-plane and ac-plane of CePtSb and polycrystals of CePtSb and LaPtSb. The carrier concentrations in ac-plane and ab-plane were estimated to be 0.042 and 0.182 per molecule from...
The optical conductivity spectra were obtained in the single crystal with ab-plane and ac-plane of CePtSb and polycrystals of CePtSb and LaPtSb. The carrier concentrations in ac-plane and ab-plane were estimated to be 0.042 and 0.182 per molecule from intraband transition, respectively, which is consistent with the result of electrical resistivity. From analysis of interband transitions, the 4d state of Pt-ion in ac-plane ties in about 1.1eV lower energy than that in ab-plane while the 4f state of Ce-ion does about 2.8eV higher. The energy shift of these band causes the anisotropy of carrier concentration.