Low-temperature Synthesis of (K_(0.5)Na_(0.5))NbO3 Nanopowders by an Urea Sol-Gel Combustion Method

摘要

Lead-free piezoelectric (K_(0.5)Na_(0.5))NbO3 nanopowders were synthesized by urea sol-gel combustion method using freshly prepared Nb2O5·nH2O and alkali hydroxides as starting materials and urea as a fuel. The effects of metal cation/urea molar ratio and calcination temperature on the crystalline phase formation of (K_(0.5)Na_(0.5))NbO3 were systematically investigated. The results showed that at a metal cation/urea molar ratio of 1:1, the single crystalline (K_(0.5)Na_(0.5))NbO3 nanopowders, with an average grain size of 15nm, were synthesized at calcination temperatures as low as 400 °C.