PHASE EVOLUTION AND MICROWAVE DIELECTRIC PROPERTIES OF Ca0.61Nd0.26Ti1-x (Al1/2Nb1/2)xO₃ CERAMICS (0 ≤ x ≤ 0.2)

Phase evolution and microwave dielectric properties of Ca0.61Nd0.26Ti1-x(Al1/2Nb1/2)xO₃ ceramic in the range of 0 ≤ x ≤ 0.2 have been determined in this paper. For 0 ≤ x ≤ 0.1, X-ray diffraction results showed a single perovskite phase. Dielectric constant (ε r) and quality factor (Qxf) kept high values and temperature coefficient of resonant frequency (τf) decreased by 32.4% from 247 ppm/°C to 167 ppm/°C. When 0.15 ≤ x ≤ 0.2, extra peaks with peak positions coincidental with Ca₂Nb₂O₇ phase appeared. Typically, high relative permittivity (≥ 90) and quality factor (≥ 6,400 GHz) could be obtained when sintered at 1400 °C for 2h.