Microwave Dielectric Properties of CuO-V2O5-Bi2O3-Doped ZnNb2O6 Ceramics with Low Sintering Temperature

Abstract

Microwave dielectric properties of low temperature sintering ZnNb 2 O 6 ceramics doped with CuO-V 2 O 5 -Bi 2 O 3 additions were investigated systematically. The co-doping of CuO, V 2 O 5 and Bi 2 O 3 can significantly lower the sintering temperature of ZnNb 2 O 6 ceramics from 1150 to 870 • C. The secondary phase containing Cu, V, Bi and Zn was observed at grain boundary junctions, and the amount of secondary phase increased with increasing CuO-V 2 O 5 -Bi 2 O 3 content. The dielectric properties at microwave frequencies (7-9 GHz) in this system exhibited a significant dependence on the relative density, content of additives and microstructure of the ceramics. The dielectric constant (ε r ) of ZnNb 2 O 6 ceramics increased from 21.95 to 24.18 with increasing CuO-V 2 O 5 -Bi 2 O 3 additions from 1.5 to 4.0 wt%. The quality factors (Q × f ) of this system decreased with increasing CuO-V 2 O 5 -Bi 2 O 3 content and ranged from 36118 to 67100 GHz for sintered ceramics, furthermore, all Q × f values of samples with CuO-V 2 O 5 -Bi 2 O 3 additions are lower than that of un-doped ZnNb 2 O 6 ceramics sintered at 1150 • C for 2 h. The temperature coefficient of resonant frequency (τ f ) changed from −33.16 to −25.96 ppm/ • C with increasing CuO-V 2 O 5 -Bi 2 O 3 from 1.5 to 4.0 wt%.

Physical property exploration of highly oriented V2O5 thin films prepared by electron beam evaporation

“…The lattice imperfection nature could be decreased due to the crystallite size decrement. 40 The evaluated microstrain values are inversely proportional to the crystallite size of the films. This may be due to an enhancement of internal microstrain with decrease in the crystallite size of the films.…”

Low temperature sintering and microwave dielectric properties of CoZrNb2O8 ceramics with H3BO3 addition

“…In general, liquid phase sintering by adding glass or low melting point materials such as H 3 BO 3 , Sb 2 O 5 and V 2 O 5 is known to be effective and the inexpensive way to obtain dense sintered ceramics [15][16][17][18]. In our previous work, the effects of H 3 BO 3 addition on the sintering behavior and microwave dielectric properties of MgZrNb 2 O 8 were investigated by solid-state method.…”

Direct Control of Defects on Positron Lifetimes and Dielectric Constant of Microwave Ceramics

“…Herein, a general microwave dielectric system ZnNb 2 O 6 doped with TiO 2 has been studied. It is worth noting that ZnNb 2 O 6 is a typical microwave dielectric material with excellent dielectric property . The dopant Ti having the similar ionic radius with Nb (the radii of Nb 5+ and Ti 4+ are 0.605 and 0.64 Å, respectively) is a typical valence electron changeable element to introduce positively charged oxygen vacancies and negatively charged Ti′ Nb into the lattices .…”