Dielectric properties of (1-y)Ca1-xLa2x/3TiO3-y(Li,Nd)(1/2)TiO3 ceramic system at microwave frequency

The solid solution of dielectric ceramic Ca1-xLa2x/3TiO3 system for the com position range of 0.1 less than or equal to x less than or equal to 0.9 is studied. The crystal structure of the system is single perovskite. From the X-ray diffraction patterns, the superstructure reflection lines are detect ed for the composition x greater than or equal to 0.5. With an increase in the substitution amount of La, the permittivity and the temperature coeffic ient of resonant frequency (TCF) decrease. A maximum Q x f value of 17600 a ppears at x = 0.4 since that the extrinsic origin for the dielectric loss d egrades the e x f value due to the poor grain growth for the composition x greater than or equal to 0.5. (1-y)Ca1-xLa2x/3TiO3-y(Li,Nd)(1/2)TiO3 compou nds are introduced to obtain a good temperature stability of resonant. freq uency, With x = 0.4, the composition y = 0.5 shows good temperature stabili ty (tau (f) = +4.5ppm/degreesC) with a high permittivity of 105 and Q x f v alue of 7000 GHz. (C) 2001 Elsevier Science Ltd. All rights reserved.