Dielectric spectra of some ceramics for microwave applications in the range of 1010–1014Hz

Abstract
The complex permittivity spectra of the alumina A12O3, mixed perovskites CaTiO3-La(Mg1/2Ti1/2)O3, (Zr,Sn)TiO4 and BaO. 4TiO2. Nd2-xSm x O3 ceramics have been determined employing various techniques in the 1010–1014 Hz range. In samples with minimized loss its origin is lattice phonon absorption in the whole spectral range. In not optimized samples the microwave losses are appreciably higher (probably due to localized hopping of charged defects) but submillimetre losses remain unaffected. Extrapolating the submillimetre loss using the proportionality ε″“(v)x v allows one to estimate the lower limit of microwave loss achievable by any processing.