Nd-doped BiFeO3 ceramics with antipolar order

Bi1-xNdxFeO3 (0 <= x <= 0.2) ceramics have been investigated using x-ray diffraction (XRD) and electron diffraction (ED). XRD patterns for x <= 0.1 were consistent with rhombohedral BiFeO3, whereas those for x=0.15 and x=0.2 exhibited peak splitting and superlattice reflections representative of orthorhombic, antiferroelectric PbZrO3. ED for the latter samples confirmed the presence of 1/4(hk0) superlattice reflections typical of a PbZrO3-like structure but additional superlattice reflections were observed at 1/4(00l) yielding a root 2a, 2 root 2a, 4a (where a is the pseudocubic lattice parameter) unit cell. The transition from rhombohedral BiFeO3 to the PbZrO3-like structure implies a modification from polar to antipolar behavior. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3097222]