Low-Temperature Sintering of Microwave Dielectrics (Zn,Mg)TiO₃

Abstract

Dielectrics (Zn,Mg)TiO3, having a high dielectric constant and a near zero temperature coefficient of resonant frequency are promising materials for microwave applications. In this work, Bi2O3 was added to (Zn,Mg)TiO3 as a low-temperature-sintering dopant. The addition of Bi2O3 significantly improved the densification of (Zn,Mg)TiO3, which were densified below 1000°C. In addition, the decomposition temperature of (Zn,Mg)TiO3 increased as the magnesium substitution increased. Microwave dielectric properties of (Zn,Mg)TiO3 ceramics depend on crystalline structure. By properly adjusting the amount of magnesium, a small temperature coefficient of resonant frequency was obtained for (Zn,Mg)TiO3 dielectrics.

Influence of V2O5 additions to 0.8(Mg0.95Zn0.05)TiO3–0.2Ca0.61Nd0.26TiO3 ceramics on sintering behavior and microwave dielectric properties

“…Ca 0.6 Nd 0.8/3 TiO 3 has a high ε r of around 98, a Q × f value higher than 8600 GHz and a τ f value of 247 ppm/ • C [5,7]. And, with partial replacement of Mg by Zn, the (Mg 0.95 Zn 0.05 )TiO 3 ceramics was investigated to possess excellent dielectric properties with an ε r value ∼16.21, a Q × f value ∼240,000 GHz (at 9 GHz) and a τ f value ∼−60 ppm/ • C [6][7][8][9][10].…”

“…Another method applied for lowering the sintering temperature was a novel chemical processing method, which often required a flexible procedure that increased the cost and time in fabrication. In previous studies, liquid phase fluxes such as B 2 O 3 , CuO, V 2 O 5 and Bi 2 O 3 were introduced as sintering aids to lower the sintering temperature of ceramics and obtain good dielectric properties [9][10][11][12][13][14][15][16][17].…”

Influence of B2O3 additions to 0.8(Mg0.95Zn0.05)TiO3-0.2Ca0.61Nd0.26TiO3 ceramics on sintering behavior and microwave dielectric properties

“…Ca 0.6 Nd 0.8/3 TiO 3 has a high ε r of around 98, a Q × f value higher than 8600 GHz and a τ f value of 247 ppm/ • C [7]. And, with partial replacement of Mg by Zn, the (Mg 0.95 Zn 0.05 )TiO 3 ceramics was investigated to possess excellent dielectric properties with an ε r value ∼16.21, a Q × f value ∼240,000 GHz (at 9 GHz) and a τ f value ∼−60 ppm/ • C [8][9][10].…”

A miniaturized bandpass filter fabricated on high dielectric constant ceramic substrates

“…Besides, a high quality factor is needed for microwave dielectrics to improve selectivity, and low temperature variation of the dielectric material's resonant frequency is also required so that the microwave components remain stable over their operating temperatures. Microwave ceramic dielectrics (Zn,Mg)TiO 3 , having high relative dielectric constant ( r ), high quality factor (Q) and near zero temperature coefficient of resonant frequency ( f ) can meet these demands and were developed in our recent study [1].…”

“…In recent years, it has been demonstrated by various groups that novel devices can be realized using electromagnetic bandgap (EBG) structures, a class of metamaterials. EBG structures, also known as photonic bandgap structures (PBG) [1,2] in optics, are now finding numerous applications at microwave and millimeterwave frequencies [3,4]. In general, EBG structures consist of periodic dielectric or metallic elements, and exhibit forbidden frequency bands (bandgap).…”