Abstract
Polarized infrared reflectivity measurements have been made on single-crystal LiTa in the frequency range 20 - 10 000 at 300 °K. Kramers-Kronig and classical-oscillator dispersion-theory analyses of these data have yielded values for the frequency, strength, and linewidth of the infrared-active transverse optic modes and longitudinal optic modes. Analysis of the far-infrared interference spectrum yields values of 41 and 40 for the ordinary and extra-ordinary clamped dielectric constants, as well as values for their temperature dependence and dispersion. A calculation is made of the spontaneous polarization in LiTa and LiNb using the x-ray ion displacements.
- Received 25 May 1970
DOI:https://doi.org/10.1103/PhysRevB.2.4233
©1970 American Physical Society