Microwave Dielectric Properties of AZn2(PO4)2(A = Sr, Ba) Ceramics

Crystal structures, microstructure and microwave dielectric properties were investigated for dense ceramics with single phase of AZn2(PO4)2 (A = Sr, Ba). It was found that crystal structures with large difference can be obtained in SrZn2(PO4)2 and BaZn2(PO4)2, which leads distinct variation of sintering and microwave dielectric properties, in which SrZn2(PO4)2 ceramics has ϵ = 6.29, Q × f = 21600 GHz (10.9 GHz) and τf = − 70.4 ppm/°C when sintering temperature was 940°C, and can be co-fired with copper electrode in N2 atmosphere; while the BaZn2(PO4)2 ceramics could be sintered at a relative higher temperature, 1000°C but higher τf value was obtained, with microwave dielectric properties as ϵ = 7.72, Q × f = 17000 GHz (9.9 GHz) and τf = − 41.1 ppm/°C.