Abstract
A surface layer ("skin") different from the bulk was found in single crystals of BiFeO(3). Impedance analysis and grazing incidence x-ray diffraction reveal a phase transition at T* similar to 275 +/- 5 degrees C that is confined within the surface of BiFeO(3).
X-ray photoelectron spectroscopy and refraction-corrected x-ray diffraction as a function of incidence angle and photon wavelength indicate a reduced electron density and an elongated out-of-plane lattice parameter within a few nanometers of the surface. The skin will affect samples with large surface to volume ratios, as well as devices that rely on interfacial coupling such as exchange bias.