A new sol-gel process for preparing Ba(Mg_1/3Nb_2/3)O₃ nanopowders

Commercially available niobium (V) oxide Nb₂O₅, with barium acetate Ba(CH₃COO)₂ and magnesium acetate Mg(CH₃COO)₂·4H₂O was used as the starting material in the sol-gel process for preparing Ba(Mg_1/3Nb_2/3)O₃ (BMN) nanopowders.At first, Nb₂O₅ reacted with melting sodium hydroxide and transformed into dispersible oxide. The resulting glassy substance after cooling was dispersed and washed several times in distilled water to remove the Na⁺ ions. The as-prepared colloidal Nb₂O₅·nH²O was subsequently mixed with acetic solution of barium acetate and magnesium acetate according to the required molar proportions and followed by gelation. The ultrafine BMN powders were finally obtained after heat-treating the gel at 820℃ for 1 h, and the assintered nanoceramics revealed a high relative density of 98.2%, and a high microwave Q-factor, of 10397 at 1.45GHz.