Structurally frustrated relaxor ferroelectric behavior in CaCu 3 Ti 4 O 12

Abstract

Direct diffraction evidence for structurally frustrated relaxor ferroelectric behavior in the form of one-dimensionally correlated, off-center displacements of Ti ions within the TiO6 octahedra of CaCu3Ti4O12 (CCTO) has been obtained. When coupled with the observation of a ferroelectric effect, important implications for the understanding of the extraordinary dielectric properties of CCTO arise. That the incipient ferroelectric behavior is correlated only along one-dimensional 001 columns of TiO6 octahedra in the absence of an applied electric field offers a crucial insight into the underlying nature of CCTO and suggests the existence of a unique class of structurally frustrated, ferroelectric relaxors.