The dielectric properties for (Nb,In,B) co-doped rutile TiO2 ceramics

Recently, colossal permittivities (similar to 10(5)) and low loss factors (< 0.1) were reported in (Nb+In) co-doped rutile TiO2 ceramics, which have attracted considerable attention. In this work, (Nb,In,B) co-doped rutile TiO2 ceramics were investigated for achieving temperature-and frequency-stable dielectric properties in TiO2 based colossal dielectric ceramics. The (Nb,In,B) co-doped rutile TiO2 ceramics were prepared by conventional solid-state reaction method. The microstructures, dielectric properties and complex impedance of 1 mol.% (Nb+In) co-doped rutile TiO2 (TINO) and xwt% B2O3 (x=0.5, 1, 2 and 4) doped TINO were systematically investigated and compared. It was found that by doping B2O3 the sintering temperature of TINO ceramics can be reduced by 100 degrees C. Meanwhile, the dielectric loss of TINO ceramics was decreased by doping B2O3. In the (2)wt% B2O3 doped TINO ceramics, the dielectric permittivity kept a high value of >2.0x10(5) and the dielectric loss was lower than 0.1 in a frequency range of 10(2)-10(5) Hz and a temperature range of 25-200 degrees C.