Microwave Dielectric Properties and Thermally Stimulated Depolarization Currents of (1− x )Ba(Mg 1/3 Nb 2/3 )O ₃ – x BaSnO ₃ Solid Solutions

Microwave dielectric ceramics of (1− x )Ba(Mg 1/3 Nb 2/3 )O 3 ‐ x BaSnO 3 [(1− x ) BMN ‐ x BS] with high quality factors was synthesized by the solid‐state reaction method. The effects of BaSnO 3 additions ( x = 0–0.2) on the sinterability, crystal structures, microwave dielectric properties, and microwave dielectric loss mechanisms of BMN were investigated systematically. The degree of 1:2 cation ordering was decreased with increasing Sn content and eventually faded away as x ≥ 0.1, where the low‐temperature relaxations disappeared coincidently through the thermally stimulated depolarization current technique. It was supposed to be the short‐range misplacements of the B‐site cations within the long‐range ordered structure. Meanwhile, the high‐temperature relaxations associated with the in‐grain oxygen vacancies were found in all the title compounds. Though the concentrations of oxygen vacancies of 0.8 BMN ‐0.2 BS were higher than BMN , high Q × f values could also be obtained even in the absence of 1:2 cation ordering. Specifically, the excellent characteristics like ε r = 29.02, Q × f = 90 000 GHz and τ f = 6.3 ppm/°C were achieved in the specimens of x = 0.2 sintered at 1450°C.