MICROWAVE DIELECTRIC CHARACTERISTICS OF THE Ca2/5Sm2/5TiO3-Li1/2Nd1/2TiO3 CERAMICS

Microwave dielectric properties of the (1-x)Ca2/5Sm2/5TiO3-xLi1/2Nd1/2TiO3 ceramics were investigated in the range of 0.2 less than or equal to x less than or equal 0.8. The unloaded Q values and the temperature coefficients of the resonant frequency (TCF) of the specimens decreased with increasing Li1/2Nd1/2TiO3. Nearly zero TCF value composition with high dielectric constant was obtained at x=0.3. Dielectric constant increased with an increase of Li1/2Nd1/2TiO3, and showed a maximum value around x=0.6, and then decreased with further addition of Li1/2Nd1/2TiO3. The change in the dielectric constant of the specimens with the addition of Li1/2Nd1/2TiO3 could be explained by the intrinsic factor such as lattice anharmonicity, which was obtained from the far ir reflectivity spectra in the range of 50 to 4000 cm-1. 20 refs.