Domain tuning in mixed-phase BiFeO3 thin films using vicinal substrates

The structural and ferroelectric domain variants of highly strained BiFeO3 films grown on vicinal LaSrAlO4 substrates were studied by piezoelectric force microscopy and high-resolution x-ray reciprocal space mapping. Through symmetry breaking of the substrate surface, ferroelastic domain variants in the highly strained MC phase BiFeO3 can be greatly reduced in thinner, purely tetragonal-like films. More interestingly, in thicker, mixed phase films, the structural variants can also be tailored by substrate vicinality. These findings lead to better understanding of the phase evolution and polarization rotation process in the strain-driven polymorphic phase system. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4717986]