Neutron diffraction study of field-cooling effects on the relaxor ferroelectric Pb[(ZnNb)Ti]O

Owada, Kenji; Hirota, Kazuma*; Rehrig, P. W.*; Fujii, Yasuhiko*; Shirane, Gen*

High-temperature () and high-electric-field () effects on Pb[(ZnNb)Ti]O (PZN-8%PT) were studied comprehensively by neutron diffraction in the ranges ~K and ~kV/cm. We have focused on how phase transitions depend on preceding thermal and electrical sequences. In the field cooling process (FC, ~kV/cm), a successive cubic (C) tetragonal (T) monoclinic (M) transition was observed. In the zero field cooling process (ZFC), however, we have found that the system does transform to the rhombohedral (R) phase as widely believed, but to a new, unidentified phase, which we call X. X gives a Bragg peak profile similar to that expected for R, but the -axis is always slightly shorter than the -axis. As for field effects on the X phase, it transforms into the M phase via another monoclinic phase (M) as expected from a previous report [Noheda , 224101 (2002)].