Temperature stable (1-y)Zn1-xGaxZrTa2O8+x/2-yZnTa2O6 microwave dielectric ceramics with ultra-low loss

Ga 3+ heterovalent substitution for Zn 2+ was beneficial for modifying ZnZrTa 2 O 8 ceramic. The enlarged Q × f was caused by a combination of grain size and total lattice energy U Total increase. The improvement of τ f was attributed to the increase in Ta-O bond energy. Zn 0.99 Ga 0.01 ZrTa 2 O 8.005 ceramics exhibited optimal Q × f of 103,236 ± 2155 GHz (@7.38 GHz) and τ f = -17.65 ± 1.61 ppm/℃. The improved τ f provided great convenience for gaining temperature stable dielectric ceramics. Afterward, ZnTa 2 O 6 as a temperature compensator was added to adjust the τ f to zero. The Zn 0.99 Ga 0.01 ZrTa 2 O 8.005 dissolved into ZnTa 2 O 6 lattice. As a result, 0.4Zn 0.99 Ga 0.01 ZrTa 2 O 8.005 -0.6ZnTa 2 O 6 ceramic sintered at 1350 ℃ obtained the desirable dielectric properties: ε r = 28.18 ± 0.01, Q × f = 81,919 ± 394 GHz (@6.70 GHz), τ ƒ = -0.51 ± 0.06 ppm/℃.