Large ferroelectric polarization in antiferromagnetic BiFe0.5Cr0.5O3 epitaxial films

Multiferroic BiFe0.5Cr0.5O3 solid solution epitaxial films were grown by pulsed laser deposition on SrTiO3 (001) substrates with SrRuO3 bottom electrodes. Formation of the metastable composition in the form of high-quality epitaxial films was made possible by a sequential deposition of 0.1 unit cell amounts of BiFeO3 and BiCrO3. The random distribution of Fe and Cr cation results in a linear response of magnetization with varying magnetic field, consistent with a dominant antiferromagnetic order. Polarization measurements at 77.3 K reveal ferroelectric hysteresis with a remanent polarization as high as 60 +/- 1 mu C/cm(2) along the pseudocubic [001] direction. (C) 2007 American Institute of Physics.