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

摘要

Structural phase transformations in (100)-oriented Pb(InNb)O-Pb(MgNb)O-PbTiO single crystals have been investigated by X-ray diffraction. A cubic (C) → tetragonal (T) → monoclinic-C (M) transformation sequence was observed in the field-cooled condition. Two phase coexistence regions of C + T and T + M were found. In addition to an increase in the C → T phase transition temperature and a decrease of the T → M 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 phase regions.