Reflectance anisotropy of Gd_(5)Si_(2)Ge_(2) and Tb_(5)Si_(2.2)Ge_(1.8)

摘要

Reflectance difference (RD) spectra for the a-b plane of the single crystals of Gd_(5)Si_(2)Ge_(2) and b-c planes of Gd_(5)Si_(2)Ge_(2) and Tb_(5)Si_(2.2)Ge_(1.8) were obtained in the photon energy range of 1.5-5.5 eV. Several peaks were observed for these crystals in the measured spectrum range. Similar features were observed in the RD spectra for the b-c planes of Gd_(5)Si_(2)Ge_(2) and Tb_(5)Si_(2.2)Ge_(1.8), while different features were observed for the a-b plane and b-c plane of Gd_(5)Si_(2)Ge_(2). The RD spectra for the crystals arise not only from the surface anisotropy but also from the bulk anisotropy due to the monoclinic structure of the bulk crystal.