Effect of P-site ion substitution with Nb5+on the structure and microwave dielectric properties of LiMgPO4 ceramics

Abstract

LiMg(P1-xNbx)O4 (0.02 ≤ x ≤ 0.08) ceramics with low permittivity were successfully prepared by the traditional solid-state reaction method at 1000–1100 °C. The phase composition, sintering characteristics and microwave dielectric properties of Nb5+ substituted LiMgPO4 ceramics have been systematically studied and analyzed in detail. The relative density of LiMg(P1-xNbx)O4 ceramics was greater than 94%, which indicates that all samples have achieved dense sintering. The solid solution limit of Nb5+ was close to 0.04 mol and the introduction of Nb5+ greatly improved the properties of LiMgPO4 ceramics. The τf values were not significantly affected by doping of Nb5+ at the P-site. When the LiMg(P0.96Nb0.04)O4 ceramic was sintered at 1050 °C, the microwave dielectric properties were εr = 7.33, Q × f = 86848 GHz, and τf = −45 ppm/°C.