Fabrication of nanopowders by high energy ball milling and low temperature sintering of Mg2SiO4 microwave dielectrics

Mg2SiO4 nanopowders were prepared from MgO and SiO2 mixtures by using a high energy ball milling method, combined with subsequent calcination at low temperatures. After milling for 30 h, pure phase Mg2SiO4 nanopowders with an average grain size of 147.4 nm were obtained at 850 °C, 300 °C lower than that required by a conventional solid state reaction process. Mg2SiO4 ceramics sintered at a low temperature of 1075 °C showed almost full density and excellent microwave dielectric properties (ɛr = 7.2, Q × f = 193,800 GHz, τf = −58 ppm/°C).

► Mg2SiO4 nanopowders were prepared by using a high energy ball milling method.
► Milling for 30 h, pure Mg2SiO4 nanopowders with an average grain size of 147.4 nm were obtained at 850 °C.
► Mg2SiO4 ceramics sintered at a low temperature of 1075 °C.
► The ceramics show almost fully density and excellent microwave dielectric properties (ɛr = 6.9, Q × f = 193,810 GHz, τf = −58 ppm/°C).