The infrared spectral emittance of single scrystals of YV has been examined near 4.2 and 77°K in the wavelength range 4-125 μm. Of the expected seven active transverse optical modes at k∼0, six have been observed and assigned to their symmetry species based on their polarization with respect to the crystalline axes. The observed frequencies of the transverse optic modes were 196, 261, and 788 ; and for modes, 310, 455, and 803 . The relation between emittance and reflectance, in the opaque region of lattice vibrations, permits one to determine the reflectance . By least-square-fitting the reflectance data to an independent set of damped harmonic oscillators, infrared dispersion parameters were determined for the vibrations.
- Received 13 November 1967
©1968 American Physical Society