Polarized Reflectivity Spectra of Tetragonal GeO2

Polarized infrared reflection spectrum of tetragonal GeO2 has been measured in the region 130–1400 cm−1. Three main resonances, corresponding to the E lim →u type modes of the D4h point group, are observed in the E lim →⊥c spectrum with the TO frequencies at 334, 652, and 709 cm−1 and LO frequencies at 484, 680, and 852 cm−1. The E lim →∥c spectrum consists of one broad band, corresponding to the A2u-type mode, with the TO at 522 cm−1 and the LO frequency at 816 cm−1.