New perovskite oxides of the type (Ln_(1/3)Ba_(1/3)Ca_(1/3))(Zn_(1/3)Ti_(2/3))O_(3-δ): Rietveld analysis and dielectric properties

摘要

Pure phases were obtained for the oxides (Ln_(1/3)Ba_(1/3)Ca_(1/3))(Zn_(1/3)Ti_(2/3))O_(3-δ) in case of Ln = La, Pr and Nd. These oxides crystallized in a cubic structure as observed from Rietveld refinement of powder X-ray diffraction studies and do not show any ordering of the cations. All the three compounds exhibit highly stable dielectric properties with respect to frequency (in the range 50-500 kHz) and temperature (35-300℃). The dielectric constant depends on the size of the cations and varies from 81 for the La-based oxide to 70 for the Nd-based oxides. The dielectric loss is in the range of 0.003-0.004 for all the three oxides at 100 kHz.