Monoclinic M(B) phase and phase instability in [110] field cooled Pb(Zn(13)Nb(23))O(3)-4.5%PbTiO(3) single crystals.

We report the finding of a monoclinic M(B) phase in Pb(Zn(13)Nb(23))O(3)-4.5%PbTiO(3) single crystals. High precision x-ray diffraction investigations of [110] field cooled crystals have shown a transformation sequence of cubic(C)-->tetragonal(T)-->orthorhombic(O)-->monoclinic(M(B)), which is different from that previously reported [A.-E. Renault et al., J. Appl. Phys. 97, 044105 (2005)]. Beginning in the zero-field-cooled condition at 383 K, a rhombohedral (R)-->M(B)-->O sequence was observed with increasing field. Coexisting M(B) and O phases were then found upon removal of field, which fully transformed to M(B) on cooling to room temperature.