Ultralow-Temperature Synthesis and Densification of Ag2CaV4O12 with Improved Microwave Dielectric Performances

At extremely low temperatures, Ag2CaV4O12 was easily synthesized using the traditional solid-state approach. With a low relative permittivity (epsilon(r)) of 7.52, a high quality factor (Q x f) of 48 800 GHz (f = 13.6 GHz), and a temperature coefficient of resonance frequency (tau(f)) of -77.4 ppm/degrees C, dense ceramics sintered at 480 degrees C with outstanding microwave dielectric characteristics were attained. By combining with rutile TiO2, a composite ceramic with balanced microwave dielectric properties (tau(f) = 3.2 ppm/degrees C, epsilon(r) = 10.96, and Q x f = 49 081 GHz) was achieved. No chemical reaction between Ag2CaV4O12 and silver and aluminum occurred. All of the findings show that Ag2CaV4O12 has the potential to be used as dielectric resonances in wireless communication and as substrates in low-temperature cofired ceramics. Furthermore, the processing at an ultralow temperature of Ag2CaV4O12 shows that it is extraordinarily energy saving from the point of view of fabrication and might allow for room-temperature synthesis by combining with high-energy mechanical milling or sintering using a high pressure such as hot isostatic pressing (HIP), spark plasma sintering (SPS), and cold sintering (CS).

Automated summary

Ag2CaV4O12 can be easily synthesized at extremely low temperatures using traditional solid-state methods, and possesses excellent microwave dielectric properties when sintered at 480 degrees C. By combining with TiO2, a composite ceramic with balanced microwave dielectric properties can be achieved. The potential applications of Ag2CaV4O12 include wireless communication as dielectric resonators and substrates in low-temperature cofired ceramics, with the added benefit of energy-saving processing.