Phase Composition, Raman Spectrum and Microwave Dielectric Properties of glass-free low temperature co-fired ACaPr(MoO4)3 (A = Na, K) Ceramics

Abstract

A novel low-temperature sintered ACaPr(MoO4)3 (A = Na, K) microwave dielectric material was prepared by the conventional solid-phase reaction method. The effects of temperatures on the crystal structure, lattice vibration characteristics, and microwave dielectric properties of the new ternary molybdate ACaPr(MoO4)3 (A = Na, K) ceramics were investigated. XRD and Rietveld refinement results show that ACaPr(MoO4)3 (A = Na, K) ceramics belong to a tetragonal scheelite structure with space group I41/a. The lattice vibration mode was analyzed by Raman spectroscopy. The ACaPr(MoO4)3 (A = Na, K) ceramics have high density(＞95%) and excellent microwave dielectric properties with εr = 10.78, Qf = 57726 GHz, τf = −44.6 ppm/°C at 775 °C and εr = 10.36, Qf = 50096 GHz, τf = −46.2 ppm/°C at 725 °C, respectively. In addition, the excellent chemical compatibility between ACaPr(MoO4)3 (A = Na, K) ceramics and Ag electrodes has developed a path for its application in LTCC technology.