TIME-RESOLVED AND BACKWARD-WAVE OSCILLATOR SUBMILLIMETRE SPECTROSCOPY OF SOME FERROELECTRIC CERAMICS AND THIN FILMS

摘要

Backward-wave oscillator spectroscopy was applied to the transmission measurements of the complex dielectric spectra in the frequency range 8-33 cm~(-1) at temperatures from 10 K to 300 K. The samples under investigation were relaxor PLZT 9.5/65/35 ceramics, antiferroelectric PbZrO_3 ceramics and thin films of Ba_xSr_(1-x)TiO_3 (x = 0; 0.1; 1) on sapphire substrates Room temperature measurements on the same samples were performed using a time-domain terahertz transmission spectroscopy in the range 3-80 cm~(-1). A good agreement of both data sets is obtained. Temperature behavior of the complex permittivity is discussed; both experimental methods are compared.