화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.101, No.1, 25-30, 2018
Controllable tau(f) value of barium silicate microwave dielectric ceramics with different Ba/Si ratios
Ba1+1/M[Si2O5+1/M] low-permittivity microwave dielectric ceramics are prepared using the conventional solid-state method. Pure phases are obtained in barium silicates with M = 1, 3, 4, 5, and , except for M = 7, in which two phases, Ba5Si8O21 and BaSi2O5, are observed. As the complexity of the crystal structure described by the Shannon information per reduced unit cell increases, the tau(f) value tends to change from a negative to a positive value, except for M = 5, which has the highest complexity. A single Ba5Si8O21 phase with epsilon(r) anomaly peak at -180 degrees C exhibits a rare positive tau(f) value (+25 ppm/degrees C), which is a novel temperature compensator.