Low-Temperature Sintering and Microwave Dielectric Properties of CuZnTiZrNbO Ceramics with the Aid of LiF.

NbO-type ceramics (where = Mg, Ca, Mn, Co, Ni, Zn and = Ti, Zr) are essential for satellite communication and mobile base stations due to their medium relative permittivity () and high quality factor ( × ). Although ZnTiZrNbO ceramic exhibits impressive microwave dielectric properties, including an of 29.75, a × of 107,303 GHz, and a of -24.41 ppm/°C, its sintering temperature of 1150 °C remains a significant barrier for integration into low-temperature co-fired ceramic (LTCC) technologies. To overcome this limitation, a strategy involving the partial substitution of Zn with Cu and the addition of LiF as a sintering aid was devised for ZnTiZrNbO. The dual impact of Cu partial substitution and LiF as a sintering enhancer facilitated the successful sintering of CuZnTiZrNbO ceramics at a reduced temperature of 950 °C using the conventional solid-state reaction method. These ceramics exhibited excellent microwave dielectric properties. Notably, CuZnTiZrNbO ceramic with 40 mol% LiF addition demonstrated optimal microwave dielectric properties without any reaction with a silver electrode at a sintering temperature of 950 °C, yielding = 32, × = 45,543 GHz, and = -43.5 ppm/°C.