Effect of Excess Li + on Microwave Dielectric Properties of Ca 0.16 Sr 0.04 Li 0.4 Nd 0.4 TiO 3 Ceramics

The effect of excess Li + ( δ ) on microstructures and microwave dielectric properties of Ca 0.16 Sr 0.04 Li 0.4 Nd 0.4 TiO 3 ceramics with δ  = 0.00125–0.0125 was investigated. XRD analysis showed that lattice parameters in a ‐axis, b ‐axis, and c ‐axis became longer by the addition of small amount of excess Li + . Ca 0.16 Sr 0.04 Li 0.4 Nd 0.4 TiO 3 ceramics with δ  = 0.0075 after being sintered at 1270°C showed the optimal values with ε r  = 138, Q.f  =   1591 GHz, and τ f  = 52 ppm/°C. Impedance measurement indicated that the grain regions showed the inhomogeneity in electrical properties and dielectric loss of the ceramic system were mainly derived from the semiconducting grain cores.