Effect of Zn2+ doping Li2Mg3Ti0.91(Al0.5Nb0.5)0.09O6 on structures and microwave dielectric properties

Li2Mg3Ti0.91(Al0.5Nb0.5)(0.09)O-6-based microwave dielectric ceramics with high dielectric constant, quality-factor and temperature stability were prepared by conventional solid-state reaction method. Influence of Zn2+ dopant on structures and microwave dielectric properties of Li2Mg3Ti0.91(Al0.5Nb0.5)(0.09)O-6 ceramics were investigated by X-ray diffraction and Raman spectroscopy. The X-ray diffraction results showed that no new phase was produced with the zinc addition before y = 0.08, above that some ZnTiO3 peaks with very low intensity appear in the low-angle region of the diffraction pattern. The results of the scanning electronic microscope confirmed that Zn2+ doping helped grains growth, reduced grain boundaries and made grains distribution uniform. All of these improvements have led to great dielectric constant (epsilon(r)), superior quality factor (Qxf) and outstanding temperature coefficient of resonance frequency (tau(f)). A microwave dielectric ceramic based on Li2Mg3Ti0.91(Al0.5Nb0.5)(0.09)O-6 with optimum Zn2+ content sintered at optimum temperature, exhibiting better comprehensive dielectric properties: epsilon(r) = 14.51, Qxf = 158,120 GHz, tau(f) = -13.0 ppm/degrees C.

Automated summary

Li2Mg3Ti0.91(Al0.5Nb0.5)(0.09)O-6-based microwave dielectric ceramics with high dielectric constant, quality factor and temperature stability were prepared. The influence of Zn2+ dopant on the structures and microwave dielectric properties was investigated. Zn2+ doping improved grains growth, reduced grain boundaries, and made grains distribution uniform, resulting in improved εr, Qxf, and τf. A microwave dielectric ceramic with optimum Zn2+ content exhibited better comprehensive dielectric properties: εr = 14.51, Qxf = 158,120 GHz, τf = -13.0 ppm/degrees C.