An intermediate antipolar phase in NaNbO3 under compression. (18th November 2017)

• Record Type: Journal Article
• Authors: Kichanov, S. E.; Kozlenko, D. P.; Belozerova, N. M.; Jabarov, S. H.; Mehdiyeva, R. Z.; Lukin, E. V.; Mammadov, A. I.; Liermann, H.-P.; Morgenroth, W.; Dubrovinsky, L. S.; Savenko, B. N.; Raevskii, I. P.; Dang, N. T.
• Is Part Of: Ferroelectrics. Volume 520(2017)
• Page Start: 22
• Page End: 33
• Publication Date: 2017-11-18
• Subjects: Ferroelectrics -- high pressure -- neutron diffraction -- X-ray diffraction -- Raman spectroscopy -- structural phase transition; Ferroelectricity -- Periodicals; Ferroelectric crystals -- Periodicals; 537
• DOI: 10.1080/00150193.2017.1374801
• Languages: English
• ISSNs: 0015-0193

Abstract

ABSTRACT: The crystal structure and vibration spectra of sodium niobate NaNbO3 have been studied by means of neutron diffraction, X-ray diffraction and Raman spectroscopy at high pressures. An isostructural phase transformation from the initial antiferroelectric phase to an intermediate antiferroelectric phase HP-I have been observed under 2 GPa. This transformation is caused by complex reorientations of NbO6 octahedra. Subsequent structural phase transition from the phase HP-I to an orthorhombic phase HP-III have been detected at pressures above 10 GPa. This transition leads to suppression of an antiferroelectric state of NaNbO3 . The observed phase transitions are accompanied by anomalies in lattice parameters compression.