Search for the X-phase in poled PZN–PT using very high-resolution single-crystal neutron diffraction

• Published in: Journal of physics. Condensed matter 2007-06, Vol.19 (23), p.232201-232201 (8)
• Main Authors: Kisi, E H, Forrester, J S, Howard, C J, Ibberson, R M
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Neutron diffraction and scattering; Niobates, titanates, tantalates, pzt ceramics, etc; Physics; Single-crystal and powder diffraction; Structure of solids and liquids; crystallography
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/23/232201

Reports that in PbZn1/3Nb2/3O3-x%PbTiO3 (PZN-PT) relaxor ferroelectric crystals an 'X-phase' exists, which has a cubic interior and a 10-50 mum thick rhombohedrally distorted surface, have been re-examined to resolve the effect of electric poling. The crystal structure of electrically poled and de-poled PZN-4.5%PT single crystals has been studied using a novel rotating single-crystal method on the high-resolution neutron powder diffractometer at the ISIS Facility. The recorded patterns are neutron time-of-flight analogues to the zero layer lines of rotating single-crystal x-ray diffraction patterns. Both [001] and [110] zones were examined and they demonstrate unequivocally that the crystals do not have a cubic core. There appears now to be direct evidence against the occurrence of the 'X-phase' in every circumstance in which, based on synchrotron studies, it was previously proposed to exist.