Microstructure and microwave dielectric properties of BaLa4Ti4O15 ceramics with template particles

BaLa4Ti4O15 (BLT) ceramic has excellent microwave dielectric properties with high dielectric constant (ɛr) and high quality factor (Q × f). However, BLT has the negative temperature dependence of resonant frequency (τf). In this study, single phase and plate-like BLT particles were prepared via a molten salt synthesis using NaCl, KCl and NaCl–KCl flux. Plate-like BLT template particles mixed with powders synthesized by solid-state reaction were uniaxially pressed and sintered. Sintered ceramics with template particles showed anisotropy in the microstructure and the crystalline phase. In the microwave dielectric properties, τf and ɛr increased with an increasing amount of template particles, and Q × f were nearly equal to that of specimens without template particles.