Microwave dielectric properties xNd(Zn1/2Ti1/2)O3-(1-x)CaTiO3 ceramics

The microwave dielectric properties of xNd(Zn1/2Ti1/2)O-3-(1-x)CaTiO3 have been investigated. The system has been prepared by a conventional solid state ceramic route. Nd(Zn1/2Ti1/2)O-3 (NZT) possesses a dielectric constant (epsilon(r)) of 32, a high quality factor (Qx f) of 170,000 GHz and a temperature coefficient of resonant frequency (tau(f)) of -42 ppm/degrees C. In order to produce a temperature-stable material, the addition of CaTiO3 leads to a near-zero temperature variation of resonant frequency. In general, the microwave quality factor (Qx f) decreased as x increased and the temperature coefficient of resonant frequency (tau(f)) was approximately linearly proportional to permittivity. The dielectric constant decreases from 77 to 32 as x varies from 0.2 to 1.0. The dielectric constant (epsilon(r)) of 45, Qx f value of 56,000 (at 6 GHz) and temperature coefficient of resonant frequency (tau(f)) of 0 ppm/degrees C were obtained for 0.5Nd(Zn1/2Ti1/2)O-3-0.5CaTiO(3) ceramics sintered at 1300 degrees C for 4 h. As the content of x increases, the highest Qx f value of 13 6,200 GHz for x=0. 8 is achieved at the sintering temperature 13 00 degrees C. (c) 2007 Elsevier B.V. All rights reserved.