Low-temperature sintering and microwave dielectric properties of CaMoO ₄-based temperature stable LTCC material

The CaMoO₄-xY₂O₃-xLi₂O ceramics were prepared by the solid-state reaction method. The sintering behavior, phase evolution, microstructure, and microwave dielectric properties were investigated. CaMoO₄ solid solution was obtained when x = 0.030, and two-phase system including tetragonal CaMoO₄ phase and cubic Y ₂O₃ phase formed when 0.066 ≤ x ≤ 1.417. A temperature stable CaMoO₄-based microwave dielectric ceramic with ultralow sintering temperature (775°C) was obtained in the CaMoO ₄-xY₂O₃-xLi₂O system when x = 0.306, which showed good microwave dielectric properties with a low permittivity of 9.5, a high Q_f value of 63 240 GHz, and a near-zero temperature coefficient of resonant frequency of +7.2 ppm/°C.