Influence of Nd doping on microwave dielectric properties of SrTiO3 ceramics

Sr1-x Nd (x) TiO3 (x = 0.08-0.14) ceramics were prepared by conventional solid-state methods. The analysis of crystal structure suggested Sr1-x Nd (x) TiO3 ceramics appeared to form tetragonal perovskite structure. The relationship between charge compensation mechanism, microstructure feature and microwave dielectric properties were investigated. Trivalent Nd3+ substituting Sr2+ could effectively decrease oxygen vacancies. This reduction and relative density were critical to improve Q x f values of Sr1-x Nd (x) TiO3 ceramics. For epsilon (r) values, incorporation of Nd could restrain the rattling of Ti4+ cations and led to the reduction of dielectric constant. The tau (f) values were strongly influenced by tilting of oxygen octahedral. The tau (f) values decreased from 883 to 650 ppm/degrees C with x increasing from 0.08 to 0.14. A better microwave dielectric property was achieved for composition Sr0.92Nd0.08TiO3 at 1460 degrees C: epsilon (r) = 160, Q x f = 6602 GHz, tau (f) = 883 ppm/degrees C.