Crystal structure and microwave dielectric properties of BaZnP₂O₇-based ceramics with Sr²⁺ substitution

In this study, Ba1-xSrxZnP2O7 (0 < x < 0.1) ceramics were synthesized at 875-950 C. The X-ray diffraction and SEM test revealed that Ba1-xSrxZnP2O7 (0 <= x <= 0.1) ceramics formed a single phase with a P-1 triclinic structure. Moreover, a moderate substitution of Sr2+ is conducive to grain growth and pore reduction. The er value was primarily affected by the average bond ionicity (Afi) and porosity, while the unit molecule polarizability contribution was insignificant. The Q x f value was closely related to the packing fraction, Utotal, and FWHM value of the strongest peak with a wavelength of approximately 1050 cm(-1) in Raman spectra. Additionally, the P-O bond significantly influenced the bond ionicity and lattice energy. The Ba0.92Sr0.08ZnP2O7 ceramic sintered at 925 C for 4 h exhibits satisfactory microwave performance: epsilon(r) = 8.26 +/- 0.06, Q x f = 61,677 +/- 1781 GHz, of = -18.34 +/- 0.21 ppm/degree celsius.