Abstract
M(2+)N(4+)Nb(2)O(8)-type ceramics (where M = Mg, Ca, Mn, Co, Ni, Zn and N = Ti, Zr) are essential for satellite communication and mobile base stations due to their medium relative permittivity (ε(r)) and high quality factor (Q × f). Although ZnTi(0.2)Zr(0.8)Nb(2)O(8) ceramic exhibits impressive microwave dielectric properties, including an ε(r) of 29.75, a Q × f of 107,303 GHz, and a τ(f) 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(2+) with Cu(2+) and the addition of LiF as a sintering aid was devised for ZnTi(0.2)Zr(0.8)Nb(2)O(8). The dual impact of Cu(2+) partial substitution and LiF as a sintering enhancer facilitated the successful sintering of Cu(0.3)Zn(0.7)Ti(0.2)Zr(0.8)Nb(2)O(8) ceramics at a reduced temperature of 950 °C using the conventional solid-state reaction method. These ceramics exhibited excellent microwave dielectric properties. Notably, Cu(0.3)Zn(0.7)Ti(0.2)Zr(0.8)Nb(2)O(8) 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 ε(r) = 32, Q × f = 45,543 GHz, and τ(f) = -43.5 ppm/°C.