Infrared dielectric response of the La2/3TiO3-LaAlO3 microwave ceramics system

Room temperature infrared reflectivity and near-millimetre transmission of (La2/3TiO3)(1-x)(LaAlO3)(x) (LTA - x) perovskite microwave ceramic system f or x = 0.04, 0.06, 0.1, 0.3 and 0.5 was measured and evaluated to obtain th e complex dielectric function and optical conductivity. Polar phonon parame ters were determined, discussed and compared with those recently found for the conducting perovskite LaTiO3. LTA - x is a low loss high permittivity d ielectric with no dispersion of permittivity between 10(9) and 10(12) Hz ra nge. In this range the dielectric losses increase roughly proportionally to frequency, as expected from the theory. This fact together with the low va lue of the losses indicates that the extrinsic losses were mainly suppresse d during the processing and the remaining microwave losses are predominantl y intrinsic (C) 1998 Elsevier Science S.A. All rights reserved.