Sintering characteristics, crystal structure and dielectric properties of cobalt-tungsten doped molybdate-based ceramics at microwave frequency

Abstract

In this study, a sequence of Ce2[Zr1‐x(Co1/2W1/2)x]3(MoO4)9 (CZ1‐x(CW)xM) (x = 0.02–0.10) ceramics with excellent microwave dielectric properties were obtained by the traditional solid-phase method. The crystal structure, dielectric properties, and chemical bond characters of the ceramics were characterized and analyzed. X-ray diffraction and Rietveld refinement analysis show that CZ1‐x(CW)xM could form a single-phase of the triangular crystal system in the entire doping range. The microstructure of the ceramic samples was obtained by scanning electron microscopy. The sintering temperature was reduced and the gain of the sample was refined as the increase of doping ion content. Furthermore, the intrinsic factors affecting the properties of CZ1‐x(CW)xM were analyzed by employing P-V-L theory and through in-depth infrared analysis. When x was 0.04 and the sintering temperature was 750 °C, the best dielectric properties of the samples were achieved, including εr = 9.95, Q·f = 80,803 GHz (at 9.99 GHz), and τf = − 9.10 ppm/°C.

Keywords

• Ce2[Zr1-x(Co1/2W1/2)x]3(MoO4)9
• Rietveld refinement
• P-V-L theory
• Infrared analysis