Na2Nb8O21 microcrystalline and ceramics prepared by molten salt synthesis

Anisometric Na2Nb8O21 particles were synthesized by a molten salt synthesis (MSS). The effects of salt content on the crystal structure and morphologies of the product powder were analyzed. The results show that the addition of excess NaCl effectively promoted the growth of product particles. The Na2Nb8O21 ceramics were prepared using the obtained particles as raw materials. It was found that all ceramic specimens exhibit relatively high transparency. The ceramics possessed optimum dielectric properties with well thermal stability of dielectric constant (Δε/εTm ≤ ± 15%) over a broad temperature range from 85 °C to 260 °C at S/O = 6.