Characterization of Extremely Low Loss Dielectrics (Mg_0.95Zn_0.05)TiO₃ at Microwave Frequency

Abstract

The microwave dielectric properties and microstructures of (Mg 0:95 Zn 0:05 )TiO 3 ceramics, prepared by a mixed oxide route, were investigated. The ceramics could be sintered at temperatures as low as 1250 C and their microwave dielectric properties were found to be strongly correlated with sintering temperature. The quality factor (Q Â f ) of (Mg 0:95 Zn 0:05 )TiO 3 increased with temperature up to 1300 C and decreased thereafter. The decrease in Q Â f was coincident with the observed abnormal grain growth. A maximum Q Â f of 264000 GHz associated with an " r of 17.1 and a f of À40:3 ppm/ C was achieved for the samples at 1300 C/4 h. Thus, (Mg 0:95 Zn 0:05 )TiO 3 is proposed as a very promising dielectric material for low-loss microwave applications.

Microwave dielectric properties of MgTiO3-based ceramics

“…Until now, various approaches have been studied to improve the Qf value of MgTiO 3 by the substitution of divalent and/or tetravalent cations for Mg 2 þ and/or Ti 4 þ [3,4]. Most of these studies discussed the relationships between the dielectric properties of MgTiO 3 -based ceramics and extrinsic factors, such as the presence of a secondary phase, the density, and microstructure [5].…”

“…In this study, the effect of cation substitution on the microwave dielectric properties of MgTiO 3 3 and milled with zirconia balls for 24 h in ethanol. The mixed powders were calcined at 1200 1C for 5 h, and these calcined powders were re-milled for 24 h, and then dried.…”

A new microwave dielectric material LiNi0.5Ti0.5O2

“…Further, the Q Â f data over the entire temperature range (1200-1300 1C) show that the specimen of LiNi 0.5 Ti 0.5 O 2 can be considered as a high-and stable-Q Â f material. The τ f value is well-known to be influenced by the composition, the additive and the second phase of the materials [19]. It was insensitive to the sintering temperature because there was no alternate composition at different temperatures.…”

Kinetic analysis on the synthesis of Mg0.95Zn0.05TiO3 microwave dielectric ceramic by polymeric precursor method

“…Hu et al [39] also investigated the kinetics of solid state reaction for Li 4 Ti 5 O 12 /C and observed Jander D3 as the most probable mechanism and the average value of activation energy for the system was 278 kJ/mol using FWO and FRL (Friedman-Reich-Levi) method. sintering method in the previous reports [6], which is most probably due to its low bulk density and porosity. As reported elsewhere, the extrinsic loss affects the quality factor values of microwave dielectric ceramics [40].…”

“…Temperature compensated bulk dielectrics of MgTiO 3 have been frequently used in the fabrication of several telecommunication devices such as low insertion loss band-pass filters, antenna diplexers, multilayer capacitors, 90° hybrid couplers, and planar patch antennas [5]. The partial replacement of Mg +2 ions by Zn +2 further enhances the quality factor of MgTiO 3 [6].…”