Abstract
The relationship between microwave dielectric properties and crystal structure of corundum-structured Mg4(Nb2-x-yTaxSby)O9 solid solutions was investigated in this study. From the XRPD patterns, a single phase of the sample which corresponded to a corundum-type structure was obtained. The Qf values of the samples was extremely improved by Ta substitution for Nb and Qf of 290000 GHz was obtained when the sample was sintered at 1600oC. However, temperature coefficient of resonant frequency was not improved by Ta and Sb substitutions for Nb.