Heteroepitaxial growth of self-assembled BaTiO₃-Fe₂O₃ nanostructures

The self-assembled growth of vertically aligned nanostructures of BaTiO₃ in the matrix of Fe₂O₃ is described. The arrays of well controlled and systematically ordered nanostructures of composite phases were grown on MgO and SrTiO₃ single crystalline substrate by using the pulse laser deposition technique under optimized conditions. The phase purities of the composite structures were characterized by using x-ray diffraction and Raman spectroscopy. The surface topographical and morphological measurements were carried out for confirming the growth on nanostructures in the composite thin films. The ferroelectric properties of these composite films were probed by electrical polarization versus electric field (P-E) measurements. The electronic and magnetic properties of the composite were studied by employing x-ray absorption spectroscopy and magnetization measurements. The presence of strain state in nanostructures is found to play an important role in modifying the crystal field effects as well as the magnetic properties of the composite compound. It is shown that the vertical self-assembly of nanorods of BaTiO₃ can be grown in the matrix layer of Fe₂O₃ on the MgO substrate by coablation.