Crystal structure and performance modification of a novel triclinic CaMgP2O7 microwave dielectric ceramic with low sintering temperature

In this study, crystal structure and microwave dielectric properties of phosphate CaMgP 2 O 7 were comprehensively investigated. As a novel microwave dielectric ceramic , CaMgP 2 O 7 consists of highly dense structure with optimal microwave dielectric properties ( ε r = 7.8 ± 0.124, Q×f = 13,165 ± 836 GHz, and τ f = −85.04 ± 1.205 ppm/℃) at a low sintering temperature (950 ℃). The Rietveld refinement of XRD patterns revealed that CaMgP 2 O 7 belongs to a triclinic system with P-1 symmetry type. Moreover, the substitution of Zn 2+ for Mg 2+ in CaMgP 2 O 7 can further reduce the sintering temperature , effectively promote the densification process, and improve the Q×f value. The effects of porosity (or density) and chemical bond characteristics on the performance of CaMg 1- x Zn x P 2 O 7 ceramics were carefully analyzed as well. Outstanding performance ( ε r = 8.05 ± 0.12, Q×f = 20,670 ± 923 GHz, and τ f = −87.59 ± 3.24 ppm/℃) can be achieved for the CaMg 0.84 Zn 0.16 P 2 O 7 ceramic sintered at 875 ℃ for 3 h.