Crystal structure of the relaxor ferroelectric PZN: demise of the 'X-phase' (letter)

Abstract

The crystal structure of lead zinc niobate (PZN) was studied by very high-resolution neutron powder diffraction using both small (<143 ?m) and large (1-2 mm) crystals. No evidence was found for the rhombohedral exterior/cubic interior 'X-phase' structure reported by Xu et al (2004 Appl. Phys. Lett. 84 3975-7). The structure is confirmed to be a rhombohedral perovskite in space group R3m. It is concluded that the X-phase observations were due to a rhombohedral domain size and population gradient within the crystals sampled by a small x-ray beam. © 2005 IOP Publishing Ltd