LAUSR

Abstract The microwave dielectric properties of ZnNi(Ti (1−x) Zr x )O 4 ceramics were examined with a view to their exploitation for mobile communication. The ZnNi(Ti (1−x) Zr x )O 4 ceramics were prepared by the conventional solid-state method. Second phase ZrO 2 was formed due to difficulty in fully replacing Ti 4+ with the relatively large Zr 4+ . With 0.01 mol Zr substitution, ZnNi(Ti 0.99 Zr 0.01 )O 4 ceramics sintered at 1550 °C for 2 h reached the maximum relative density of 97.38% and possessed a maximum average grain size of 22.32 μ m. Dielectric constant ( e r ) of 17.3, quality factor ( Q × f ) of 35,100 GHz (at 12.2 GHz) , and temperature coefficient of resonant frequency ( τ f ) of −46 ppm/°C were obtained for ZnNi(Ti 0.99 Zr 0.01 )O 4 ceramics that were sintered at 1550 °C for 2 h.