Modulation on structure and electric properties by tantalum of lead‐free NaNbO₃ ceramics

The variation of structural and electric properties is investigated via different characterization methods for NaNbO 3 ceramics modified with Ta 5+ ions. At room temperature, substitution of Ta 5+ ions can effectively induce the phase coexistence and transition between orthorhombic antiferroelectric P and orthorhombic ferroelectric Q phase in NaNb 1‐ x Ta x O 3 ceramics. Thus, the ferroelectric and piezoelectric properties could be regulated with the maximum value of d 33 (~37.3) at x = 0.05. Besides, with increasing temperature, multiple phase transitions are demonstrated through dielectric, XRD, and in situ Raman results. Moreover, the temperature of various phase transitions gradually shifts toward lower temperature with increasing Ta 5+ ions. Correspondingly, the modulation mechanism is also discussed based on the evolution of Raman vibration. This work is instructive for regulatable applications of NaNbO 3 ‐based materials.