Local structure analysis of NaNbO3

Abstract

NaNbO3 has an antiferroelectric structure at room temperature and finds important technological applications. It exhibits an unusual complex sequence of temperature-and pressure-driven structural phase transitions. NaNbO3 shows unambiguous evidence for the presence of the ferroelectric R3c phase coexisting with an antiferroelectric phase (Pbcm) over a wide range of temperatures. We have carried out atomic pair-distribution function (PDF) analysis on NaNbO3 to understand the phase transitions. High-energy X-ray PDF using powder samples were carried out at the SPring-8, which is provided to become rhombohedral structure if A-site atoms did order and to become orthorhombic structure if A-site atoms did disorder.