Effects of rare earth oxides on dielectric properties of Y2Ti2O7 series ceramics

A series of Y2Ti2O7 microwave dielectric ceramics were synthesized by conventional solid-state method. The effects of rare earth oxide (La2O3, CeO2, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Dy2O3) and Nd2O3 doping content on the microstructure and dielectric properties of Y2Ti2O7 ceramics were investigated. The experimental results showed that the rare earth ions were considered to dissolve in Y-sites of the pyrochlore structure, different rare earth oxides and concentration had different influences on Y2Ti2O7 ceramics. It was found that the rare earth oxide could decrease dielectric loss obviously, and the tf could be adjusted to zero with proper concentration. The Y2Ti2O7 ceramics with 1 mol.% neodymium oxide(Nd2O3) added showed optimum comprehensive properties, with the sintering temperature 1450 °C, the permittivity 45, the value of Q·f 22000 GHz, and the tf value 179 ppm/°C, while 1 mol.% Nd oxide (Nd2O3) was added.