Processing of low-fired glass-free Li2MgTi3O8 microwave dielectric ceramics

An approach in which the raw materials of Li2CO3, MgO and TiO2 were ball milled before mixing (abbreviated as LMT2) was reported. For the traditional ceramic technique (abbreviated as LMT1), the raw materials of Li2CO3, MgO and TiO2 were directly used without further processing. The powders from LMT2 tended to be smaller and uniform and the ceramics exhibited higher densities than that of LMT1, which significantly lowered the sintering temperature from 1075 °C to 925 °C. LMT2 ceramics sintered at 925 °C exhibited good microwave dielectric performance with εr = 27.0, Q × f = 58,480 GHz (at ∼ 5.8 GHz), τf = 0.45 ppm/°C. Moreover, LMT2 ceramic was found to be chemically compatible with Ag. The results indicate that the pretreatment of raw materials is a relatively simple and particularly effective method to obtain glass-free Li2MgTi3O8 LTCC ceramics.