1. Microstructure and microwave dielectric properties of CuO-modified CoWO ceramics.
- Author
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Zhang, Bowen and Li, Lingxia
- Subjects
DIELECTRIC properties ,MICROSTRUCTURE ,COPPER oxide ,TEMPERATURE measurements ,MICROWAVE measurements ,MATHEMATICAL models ,CRYSTALLOGRAPHY - Abstract
(1 − x)CoWO-xCuO dielectric ceramics were synthesized by the mixed oxide reaction method. W-based microwave dielectric materials with excellent properties have been reported heavily. The high sintering temperature seriously limited their commercial application in low temperature co-fired ceramics (LTCC) devices. CuO with a low melting point had been widely used as a liquid phase sintering aid. The addition of CuO had great effects on the sintering temperature, microstructure and microwave dielectric properties. When a small amount of CuO was added, the optimal sintering temperature could be decreased from 1200 to 950 °C, with no severe deterioration on the dielectric properties. The X-ray diffraction patterns indicated all samples to exhibit wolframite-like monoclinic P2/c (13) structure and no impurity phase. X-ray powder diffraction and SEM analysis revealed the formation of solutions between CoWO and CuO. Meanwhile, excellent microwave dielectric properties were obtained (permittivity of ~10.69, quality factor Q × f of ~20,000 GHz ( f = 10 GHz) and temperature coefficient of frequency τ of ~−35 ppm/°C) for 0.97CoWO-0.03CuO sintered at 950 °C. These features make (1 − x)CoWO-xCuO ceramics a promising candidate for LTCC application. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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