Effects of rare earth oxides on dielectric properties of Y ₂Ti₂O₇ series ceramics

A series of Y₂Ti₂O₇ microwave dielectric ceramics were synthesized by conventional solid-state method. The effects of rare earth oxide (La₂O₃, CeO₂, Nd ₂O₃, Sm₂O₃, Eu₂O ₃, 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 Y₂Ti ₂O₇ ceramics. It was found that the rare earth oxide could decrease dielectric loss obviously, and the t_f 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 t_f value 179 ppm/°C, while 1 mol. Nd oxide (Nd₂O₃) was added.