Fabrication nanopowders by high-energy ball-milling and low temperature sintering Li₂TiO₃ microwave dielectrics

Highlights: • Li₂TiO₃ nanopowders are prepared at 600 °C by using high-energy ball milling route. • The average particle size of Li₂TiO₃ powders is 86.7 nm. • Decreasing particle size of powders decreases the sintering temperature of ceramics. • Li₂TiO₃ ceramics are obtained at 1000 °C by using nanopowders as a precursor. • Increasing density will increase microwave dielectric properties of ceramics. - Abstract: In this study, Li₂TiO₃ nanopowders were synthesized via a high-energy ball-milling process followed by calcinations and Li₂TiO₃ ceramics were fabricated by solid-state reaction. The microstructure and microwave dielectric properties of Li₂TiO₃ ceramics were also investigated systematically. Li₂TiO₃ nanopowders with an average particle size of 86.7 nm were derived at 600 °C for 2 h. X-ray diffraction patterns exhibited that single monoclinic structure of the Li₂TiO₃ ceramics were obtained at an optimum sintering temperature of 1000 °C for 2 h by using low temperature synthesis nanopowders as a precursor. The samples of Li₂TiO₃ ceramics with grain sizes in the range of 1.5–5.0 μm showed dense microstructures and excellent microwave dielectric properties (ε_r = 16.4, Q × f = 54,326 GHz, τ_f = 27.4 ppm/°C). All these results illustrated that high-energy ball-milling method is a simple and practical route to produce Li₂TiO₃ ceramics for microwave applications