Sintering behavior, microstructure and microwave dielectric properties of Li2MgTi3O8 modified by LiF

Sintering behavior, microstructure and microwave dielectric properties of Li2MgTi3O8 ceramics modified by LiF have been studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermal dilatometry and with a network analyzer at the frequency of about 6-10 GHz. The addition of LiF to Li2MgTi3O8 led to the formation of trace amounts of MgF2(ss), and Li2TiO3(ss) secondary phases, which reduced the sintering temperature to 850 A degrees C without affecting its microwave dielectric properties. In contrast, the LiF-doped composition exhibited single phase solid solution with ordered spinel structure after sintering at 900 A degrees C/2 h, and MgTi2O5 secondary phase appeared after sintering at 1100 A degrees C/2 h. An excellent combined microwave dielectric properties with epsilon (r) of similar to 27.8, Q x f of similar to 63,000 GHz and tau (f) of similar to-4.1 ppm/A degrees C could be obtained for the LiF-added composition with x = 0.15 sintered at 850 A degrees C/2 h. The x = 0.15 composition was chemically compatible with Ag powders after sintering at 850 A degrees C for 2 h.