Effects of MgO addition on the microstructure and dielectric properties of Ba5LaZnNb9O30 ceramics with high dielectric constant

摘要: Polycrystalline Ba5LaZnNb9O30 doped with x wt% MgO (x = 1, 3, 5, 7, 10) were synthesized using a conventional solid-state reaction method. The phase structure, microstructure and dielectric properties of these ceramics investigated. Results show that addition plays an important role in achieving the low loss. Mg2+ ions can partially substitute for Zn2+ amount substitution increases x, while excess inhibits grain growth ceramics. X-ray diffraction reveals second appears when doping content exceeds 1 wt%. For increasing values constant (er) decreases monotonously from 293.73 to 162.35, loss (tanδ) greatly 0.02173 0.00047 then slightly 0.00078 at MHz, temperature coefficients (τe) reduces first changes little. sample 5 indicates high (er 186.14) (tanδ 0.00047) however τe should be improved further.