Effect of B2O3 Nano-Coating on the Sintering Behaviors and Electrical Microwave Properties of Ba(Nd2−xSmx)Ti4O12 Ceramics

Abstract. Ba(Nd0.8Sm0.2)2Ti4O12 ceramics prepared by conventional solid-state sintering have a dielectric con-stant of about 80 and a nearly zero temperature coefficient of resonant frequency; however, the sintering temperature is above 1350◦C. Doping with B2O3 (up to 5 wt%) promotes the densification and dielectric properties of BNST ce-ramics. It is found that coating BNST powder with thin B2O3 layer of about 180 nm reduces the sintering temperature to below 1020◦C. The effects of B2O3 nano-coating on the dielectric microwave properties and the microstructures of BNST ceramics are investigated. Ninety-six percent of theoretical densities is obtained for specimens coated with 2 wt % B2O3 sintered at 960◦C and the samples exhibit significant (002) preferred orientation and columnar structure