LAUSR

Abstract Phase formation, crystal structure and dielectric properties of NaCa4V5O17 ceramics fabricated via a solid state reaction route at relatively low temperatures (780–860 °C) were investigated. NaCa4V5O17 crystallizes in a triclinic structure. Dielectric properties were measured based on the Hakki-Coleman post resonator method at microwave frequency. Specially, a specimen sintered at 840 °C demonstrated balanced dielectric properties with a permittivity er = 9.72, a quality factor Q×f = 51,000 GHz, and a temperature coefficient of resonance frequency τf = −84 ppm/°C. NaCa4V5O17 ceramics showed excellent chemical compatibility with Ag metal electrodes. Besides, the thermal stability of resonance frequency was effectively adjusted through formation of composite ceramics between NaCa4V5O17 and TiO2 and a near-zero τf ˜ 1.3 ppm/°C accompanied with er = 14.9 and Q×f = 19,600 GHz was achieved when 50% mol TiO2 was added. All the merits render NaCa4V5O17 a potential candidate for multilayer electronic devices.