Li 2+ x ZrO 3 F x (0 ≤ x ≤1.25): A new high‐ Q × f and temperature‐stable microwave dielectric ceramic system for LTCC applications

Here we report a new high‐ Q × f and temperature‐stable oxyfluoride microwave dielectric ceramic system of Li 2+ x ZrO 3 F x (0 ≤ x ≤ 1.25) sintered at low temperatures (i.e., ≤950°C). The sintering characteristics, phase assemblage, microstructures, and microwave dielectric properties (MDPs) of the Li 2+ x ZrO 3 F x specimens were studied. The chemical bond theory calculations were employed to analyze the compositional dependence of the MDPs in the Li 2+ x ZrO 3 F x ceramic system. The optimal MDPs of ε r = 15.8, Q × f = 65 100 GHz, and τ f = 1.2 ppm/°C were achieved in the sample with x = 1. Besides, the ceramic samples exhibited high chemical compatibility with Ag electrodes. Therefore, the novel ceramic system of Li 2+ x ZrO 3 F x is confirmed to be a promising candidate as a low‐temperature co‐fired ceramic material.