Effects of B‐site Substitution on Microwave Dielectric Properties of Ba _{6−3 x} Nd _{8+2 x} [Ti _{1− z} (Ni _1/3 Nb _2/3 ) _z ] ₁₈ O ₅₄ Ceramics

According to the solid‐state reaction, microwave dielectric ceramics of Ba _{6−3 x} Nd _{8+2 x} [Ti _{1− z} (Ni _1/3 Nb _2/3 ) _z ] ₁₈ O ₅₄ ( x = 0.75, 0 ≤ z ≤ 0.2) were fabricated. Microwave dielectric properties, including relative dielectric constant (ε _r ), quality factor ( Qf ), and temperature coefficient of resonant frequency (τ _f ), were investigated as a function of substitution content. As z increasing from 0 to 0.2, dielectric constant was decreased from 87.3 to 80.4, Qf value declined from 9700 to 1200 GHz, and τ _f dropped from +60.0 to −27.0 ppm/°C. Appropriate substitution conducted excellent microwave dielectric properties with z = 0.05 sintered at 1375°C for 2 h in air: ε _r = 82.25, Qf = 6100 GHz, and τ _f = +18 ppm/°C.