Local structure analysis of Li-substituted NaNbO

Yoneda, Yasuhiro   ; Ohashi, Takayuki*; Aoyagi, Rintaro*

NaNbO is a O perovskite ferroelectric materials and has antiferroelectric orthorhombic structure at room temperature. Li-substituted NaNbO crystals show different phase transition sequence though have the same average structure. The purpose of this work was to clarify the local structures of Li-substituted NaNbO and to elucidate the mechanism of the ferroelectric phase transitions. A local structure analysis was carried out using the X-ray pair-distribution function (PDF) obtained from high-energy synchrotron X-ray diffraction. A clear difference in the local structures of Li-substituted NaNbO was found. The difference in the ferroelectric phase transition can be explained by the local environment around the -site atoms.