Advantages of Low Partial Pressure of Oxygen Processing of Alkali Niobate: NaNbO 3

This work focused on the processing of low oxygen partial pressure (low‐ p O 2 ) calcination and sintering with respect to NaNbO 3 ( NN ) of one key member in ferroelectric (Na,K)NbO 3 . The high‐density NN ceramics were successfully prepared without any sintering additives using the low‐ p O 2 process. Comparing conventional air process, the low‐ p O 2 calcined NN powders showed lower defect concentration and higher densification. The low‐ p O 2 sintered NN ceramics had dielectric constant and dielectric loss performance at high temperatures. Furthermore, the low‐ p O 2 sintered NN ceramics indicated ferroelectric behavior, and both maximum polarization and strain improved to two to three times that of conventional air‐sintered NN ceramics. From this relatively simple compound, NN , the advantage of low‐ p O 2 is unambiguously demonstrated and points to its consideration. It is hypotheses as a kinetically controlled process that limits the volatility under low‐ p O 2 condition.