Low Temperature Sintering, Structure and Microwave Dielectric Properties of Novel (1 – x)MgGa2O4–xCuMoO4 Ceramics for LTCC Applications

Fabrication of low-temperature co-fired ceramic (LTCC) densified at a low sintering temperature (<900 °C) is energy saving and environmentally friendly. Here, an interesting attempt has been made to lower the sintering temperature of MgGa2O4 by adding CuMoO4 for LTCC application. The sintering temperature of MgGa2O4 was remarkably reduced from 1410 to 900 °C, which contributed to energy saving. Furthermore, a series of studies on microstructure, sintering behavior, lattice parameters, and microwave dielectric characteristic of the samples were carried out. The occurrence of ion substitution between MgGa2O4 and CuMoO4, which affected the sintering densification, ionic polarizability, and Mg–O bond length, made the composites present various sintering and dielectric properties. Moreover, the full width half maximum (FWHM) value of the T2g peak in Raman spectra and lattice distortion were also analyzed to reveal the intrinsic interaction between structure and dielectric properties. Finally, the 0.5MgGa2O4–0.5CuMoO4 ceramics sintered at 900 °C showed the best comprehensive performance, εr = 6.8, Q × f = 15,800 GHz, τf = −54.2 ppm/°C. These promising properties make the composite more suitable for practical application.