Microwave dielectric properties of low loss microwave dielectric ceramics: A0.5Ti0.5NbO4 (A=Zn, Co)

Abstract

Abstract The microwave dielectric properties of low-loss A0.5Ti0.5NbO4 (A = Zn, Co) ceramics prepared by the solid-state route had been investigated. The influence of various sintering conditions on microwave dielectric properties and the structure for A0.5Ti0.5NbO4 (A = Zn, Co) ceramics were discussed systematically. The Zn0.5Ti0.5NbO4 ceramic (hereafter referred to as ZTN) showed the excellent dielectric properties, with ɛr = 37.4, Q × f = 194,000 (GHz), and τf = −58 ppm/°C and Co0.5Ti0.5NbO4 ceramic (hereafter referred to as CTN) had ɛr = 64, Q × f = 65,300 (GHz), and τf = 223.2 ppm/°C as sintered individually at 1100 and 1120 °C for 6 h. The dielectric constant was dependent on the ionic polarizability. The Q × f and τf are related to the packing fraction and oxygen bond valence of the compounds. Considering the extremely low dielectric loss, A0.5Ti0.5NbO4 (A = Zn and Co) ceramics could be good candidates for microwave or millimeter wave device application.