Crystal structure and microwave dielectric properties of Li4Mg3[Ti1-x(Mg1/3Ta2/3)x]2O9 (x = 0–0.4) ceramics. Issue 3 (15th February 2019) - Xing, C.F.
Abstract: A series of Li4 Mg3 [Ti1-x (Mg1/3 Ta2/3 )x ]2 O9 (LMT1-x (MT)x ) (x = 0–0.4) ceramics were prepared via the traditional solid-state method. The effects of the substitution of (Mg1/3 Ta2/3 ) 4+ on the sintering characteristic, crystal structure, phase composition and dielectric properties of Li4 Mg3 Ti2 O9 ceramics were investigated for the first time. The analysis of the X-ray diffraction pattern indicated that the pure cubic Li4 Mg3 Ti2 O9 phase could be formed in the whole composition range of 0 ≤x ≤ 0.4. Dense and homogeneous microstructures of LMT1-x (MT)x ceramics sintered at 1400–1550 °C could be revealed from the scanning electric microscope. The optimum microwave dielectric properties, with a permittivity 15.77, a quality factor 160, 575 GHz (at 8.38 GHz) and a τ f value 0 ppm/°C, were achieved in the Li4 Mg3 [Ti0.8 (Mg1/3 Ta2/3 )0.2 ]2 O9 ceramic sintered at 1550 °C.