N. Dix* R. Muralidharan, J-M Rebled, S. Estradé, F. Peiró, M. Varela, J. Fontcuberta and F. Sánchez*
ACS Nano, 2010, 4 (8), pp 4955–4961 DOI: 10.1021/nn101546r
We demonstrate that epitaxial strain engineering is an efficient method to manipulate the ferromagnetic and ferroelectric properties in BiFeO3
columnar nanocomposites. On one hand, the magnetic anisotropy of CoFe2
is totally tunable from parallel to perpendicular controlling the CoFe2
strain with proper combinations of substrate and ferroelectric phase. On the other hand, the selection of the used substrate allows the growth of the rhombohedral bulk phase of BiFeO3
or the metastable nearly tetragonal one, which implies a rotation of the ferroelectric polar axis from  to close to the  direction. Remarkably, epitaxy is preserved and interfaces are semicoherent even when lattice mismatch is above 10%. The broad range of sustainable mismatch suggests new opportunities to assemble epitaxial nanostructures combining highly dissimilar materials with distinct functionalities.