Abstract: (1-x)CaTiO_3-x(Li_1/2Sm_1/2)TiO₃ microwave dielectric ceramics were prepared by solid sate reaction technique. The crystal structure, sintering properties and microwave dielectric properties of the ceramics were investigated. The results show that a single orthorhombic perovskite structure forms in the x range from 0.1 to 0.9; the best sintering temperatures of (1-x)CaTiO_3-x(Li_1/2Sm_1/2)TiO₃ are 1250℃ and 1300℃ in the x range from 0.1 to 0.5 and 0.6 to 0.9, respectively; the dielectric constant εr, the product of quality factor and resonance frequency (Qf ) value and the temperature coefficient of resonant frequency τf decrease with the increasing of x. The Ca_0.3(Li_1/2Sm_1/2)_0.7TiO₃ ceramic sintered at 1300℃ for 5h exhibits excellent microwave dielectric properties: ε_r=116.5, Qf=3254GHz, τ_f=42.43×10^-6/℃.

Key words: Li_1/2Sm_1/2TiO₃, perovskite, microwave dielectric properties