Crystal structure, Raman spectrum, bond characteristics, and terahertz time-domain spectrum of novel Na5Tm(MoO4)4 microwave dielectric ceramic with ultra-low sintering temperature and high quality factor

This study synthesized a novel Na5Tm(MoO4)4 (NTM) ceramic through the solid-state process. A single tetragonal phase of NTM ceramic was formed when sintered at 550 degrees C-650 degrees C. Raman spectrum studied the lattice dynamics information of NTM ceramic. The influence of multiple chemical bonds in NTM ceramic on the crystal stability and dielectric properties was revealed via the Phillips-van Vechten-Levine (P-V-L) theory. Optimal dielectric properties of epsilon r = 7.66, Q center dot f = 67,499 GHz (at 10.11 GHz), and tau f = - 58.85 ppm/degrees C were achieved in NTM ceramic sintered at 625 degrees C. According to the terahertz time-domain spectrum, the dielectric constant of NTM ceramics in the terahertz band is slightly less than that in the microwave band. Furthermore, the ceramic shows good chemical compatibility with Ag powder and is suitable for low temperature co-fired ceramic (LTCC) applications. The ultra-low sintering temperature, low dielectric constant, and low dielectric loss in the microwave and terahertz frequency bands make it an excellent dielectric material for preparing high-frequency wireless communication devices. (c) 2022 Elsevier B.V. All rights reserved.