Sintering behavior, structure, and microwave properties of novel Li2xCu1-xMoO4 ceramics

In this study, we prepared a novel series of Li 2 x Cu 1- x MoO 4 ( x  = 0.02, 0.04, 0.06, 0.08, and 0.10) microwave ceramics. The dynamic sintering behavior, crystal phases, micro-morphologies, and dielectric properties of the samples were studied. The substitution of Li + contributed to refining the crystal grain size, promoting the densification of microstructure, and enhancing the quality factor. Due to different valence substitutions, Cu + ions were created, which were verified by X-ray photoelectron spectroscopy (XPS) and Raman experiments. In addition, the Raman shift, full width at half maximum (FWHM) value of the A 1g peak, and crystal microstrains were analyzed to gain a mechanistic understanding of the influence of structure on the dielectric properties . When x  = 0.08, the Li 2 x Cu 1- x MoO 4 ceramic sintered at 675 °C exhibited optimal comprehensive properties with ε r  = 8.17, Qf = 68 476 GHz, and τ f  = −25 ppm/°C, and good chemical stability between the ceramic and Al electrode was also achieved. These promising properties make Li 2 x Cu 1- x MoO 4 ( x  = 0.08) more suitable for ultra-low temperature co-fired ceramic (ULTCC) applications.