Microwave Dielectric Properties of a New Ultra Low Loss Pervoskite Ceramic

Abstract

The microwave dielectric properties and microstructures of an Mg(Zr 0.05 Ti 0.95 )O 3 ceramic system have been investigated. The compounds were prepared by the conventional solid-state route, and sintered at 13601-14501C for 2-6 h. The structure and microstructure were analyzed using X-ray diffraction and scanning electron microscopy techniques. The Mg(Zr 0.05 Ti 0.95 )O 3 had excellent dielectric properties: Q Â f 5 380 000 (GHz), e r 5 18.1, and s f 5 À50 ppm/1C for the sample at 14201C/4 h. These properties were correlated with the formation of second phases, Mg 2 TiO 4 and Mg 0.25 Zr 0.38 Ti 0.38 O 1.75 .

Effect of sintering aid on microwave dielectric properties of Mg(Zr0.05Ti0.95)O3 ceramics

“…The abnormal grain growth was obtained especially at higher B 2 O 3 content for higher sintering temperature. These may directly affect the [3]. It can be also observed that Mg 2 TiO 4 (spot C) and MgTi 2 O 5 (spot D) phase exists in 0.5 and 1.0 wt% (appeared at 1390 • C) B 2 O 3 -doped MZrT sample, respectively.…”

“…This indicates that B 2 O 3 addition effectively improves the sinterability of MZrT ceramics. The 4.53 g/cm 3 of the bulk density is obtained for pure MZrT sintering at 1420 • C for 4 h [3]. The maximum bulk density obtained decreases with the increase of B 2 O 3 content.…”

“…They have an ilmenite-type structure, belonging to the trigonal space group R3. MZrT ceramics possess high dielectric constant (ε r ∼18.1), high-quality factor (Q×f value ∼380,000 GHz), and negative f value (−50 ppm/ • C) [3]. However, despite its excellent microwave dielectric properties, the disadvantage of the MZrT material is that it requires a high sintering temperature (1420 • C).…”

“…For the 1-1.5 wt% B 2 O 3 -doped ceramics, MgTi 2 O 5 , TiO 2 and (Mg,Ti) 2 (BO 3 )O second phases increased, while that of Mg 2 TiO 4 phase disappeared. Only 3.6, 4.53 and 3.4 g/cm 3 of the bulk densities are obtained for MgTi 2 O 5 , TiO 2 and (Mg,Ti) 2 (BO3 )O second phases, respectively. Therefore, the variation of the density could be explained by the changes in the microstructure and existence of second phases.…”

The effect CuO additive on the microwave dielectric properties of Mg(Zr0.05Ti0.95)O3 ceramics

“…To further investigate the influence of equivalent-charge substitutions for B sites on MgTiO 3 , we used Zr 4+ to substitute Ti 4+ to form Mg(Zr 0.05 Ti 0.95 )O 3 (MZrT) in the previous study. Excellent microwave dielectric properties of ε r = 18.1, Q × f = 380,000 GHz and f = −50 ppm/ • C were obtained for the Mg(Zr 0.05 Ti 0.95 )O 3 ceramics [2]. However, it required sintering temperatures as high as 1420 • C. For practical application in communication systems, it is necessary to lower the sintering temperature of Mg(Zr 0.05 Ti 0.95 )O 3 ceramics.…”