Flash sintering of sodium niobate ceramics

Dense and stoichiometric NaNbO3 ceramics were difficult to be prepared by conventional sintering methods because Na2O easily volatilized at elevated temperature. In this work, the volatility of Na2O was suppressed by applying an electrical field assisted sintering method. Flash sintering was preformed successfully on NaNbO3 ceramics under the electrical fields ranging from 400 to 700 V/cm. The Na/Nb ratio of dense ceramic remained similar to that of the green sample. Our work demonstrated that flash sintering was an alternative technique for fabricating dense and high-purity ceramics with highly volatile species.