Phase coexistence and transformations in field-cooled ternary piezoelectric single crystals near the morphotropic phase boundary

Structural phase transformations in (100)-oriented Pb(In1/2Nb1/2)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystals have been investigated by X-ray diffraction. A cubic (C)-> tetragonal (T)-> monoclinic-C (M-C) transformation sequence was observed in the field-cooled condition. Two phase coexistence regions of C+T and T+M-C were found. In addition to an increase in the C -> T phase transition temperature and a decrease of the T -> M-C one, a broadening of the coexistence regions was also found with increasing field. This broadening can be explained by the presence of polar nano regions within the C, T, and M-C phase regions. (C) 2014 AIP Publishing LLC.