Microwave dielectric properties of Ba5Nb4O15 ceramic by molten salt method

Ba5Nb4O15 powders were synthesized by molten-salt method in NaCl-KCl flux at a low temperature of 650-900 degrees C for 2 h, which is lower than that of the conventional solid-state reaction. This simple process involved mixing of the raw materials and salts in a certain proportion. Subsequent calcination of the mixtures led to Ba5Nb4O15 powders at 650-900 degrees C. XRD and SEM techniques were used to characterize the phase and morphology of the fabricated Ba5Nb4O15 powders, respectively. After sintering at 1,300 degrees C for 2 h, the densified Ba5Nb4O15 ceramics with good microwave dielectric properties of epsilon(r) = 39.2, Q x f approximated as 27,200 GHz and tau(f) = 72 ppm/degrees C have been obtained.