High-Q microwave dielectrics in the (Mg1−xZnx)Al2O4 (x = 0–0.1) system

Abstract The microwave dielectric properties and the microstructures of (Mg 1− x Zn x )Al 2 O 4 ( x  = 0–0.1) ceramic system prepared by the conventional solid-state route were investigated. The forming of spinel-structured (Mg 1− x Zn x )Al 2 O 4 ( x  = 0–0.1) solid solutions was confirmed by the XRD patterns and the measured lattice parameters, which linearly varied from a  =  b  =  c  = 8.0815 A for MgAl 2 O 4 to a  =  b  =  c = 8.0828 A for (Mg 0.9 Zn 0.1 )Al 2 O 4 . By increasing x , the Q  ×  f of (Mg 1− x Zn x )Al 2 O 4 can be tremendously boosted from 82,000 GHz at x  = 0 to a maximum of 156,000 GHz at x  = 0.05. The Zn substitution was effective in reducing the dielectric loss without detrimental effects on the ɛ r and τ f values of the ceramics.