Frequency Dependent Dielectric Properties of Lead-Tin-Telluride.

摘要

The use of a new impedance matching technique to obtain values of the low frequency dielectric parameters for PbTe by far infrared reflectivity is reported. The values obtained for the transverse optical phonon were 31.3 + or - .3/cm at room temperature and 22.8 + or - .1/cm at liquid nitrogen temperature. The phonon linewidth decreased from 10.8 + or - .7/cm at room temperature to 2.1 + or - .2/cm at liquid nitrogen temperature. The values obtained did not depend strongly on other fit parameters such as plasma frequency or scale factor due to aligning errors. Conventional reflectance measurements were made on a Pb.8Sn.2Te film on PbTe. However, the values obtained for optical mode frequency had large uncertainty due to the strong interdependence of optical mode frequency and scale factor. This report also summarizes the results of earlier work on this contract. (Author)