Experiment and calculation: The Li(Zn, Mn)PO4 solid solution ceramics with low dielectric constant, high quality factor, and low densification temperature

Abstract

Abstract The microstructure, sintering and microwave dielectric properties of (1−x)LiZnPO4+xLiMnPO4 (x = 0.0–1.0) composite ceramics were discussed specifically through density functional theory calculation and solid-state reaction experiment. The (1−x)LiZnPO4+xLiMnPO4 (x = 0.0–1.0) composite ceramics were characterised using network analyser, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and differential–thermal and thermo-mechanical analyser. The solid solution of Mn2+-ion-doped LiZnPO4 ceramic and Zn2+-ion-doped LiMnPO4 ceramic formed when the LiMnPO4 ceramic was added into the LiZnPO4 ceramic. The modification of the bond length, bond population and electron density could be observed in the ZnO4 tetrahedron and MnO8 octahedron. Moreover, the densification window of the LiZnPO4 ceramic decreased slightly. Experimental results were specifically explicated by the calculation result. Peak dielectric properties were obtained when x = 0.3 sintered at 800 °C, er = 5.83, Q × f = 71,007 GHz, τf = −82.84 ppm/°C and relative density = 97.33%. The addition of the LiMnPO4 ceramic is an effective method for improving the sintering and microwave dielectric properties of the LiZnPO4 ceramic.