Epitaxial growth of multiferroic BiFeO3 thin films with (101) and (111) orientations on (100) Si substrates

Multiferroic (101)- and (111)-oriented BiFeO3 thin films were grown on heteroepitaxial substrates of (110) SrRuO3/(100) YSZ/(100) Si and (111) SrRuO3/(111) Pt/(100) YSZ/(100) Si, respectively, by pulsed laser deposition. X-ray diffraction θ–2θ scans, ϕ scans, and pole figures showed the well-developed out-of-plane and in-plane orientations of the epitaxial BiFeO3 films. The (111) BiFeO3 films showed ∼3/2 times higher remanent polarization (58.9 μC/cm2) than that of the (101) BiFeO3 films (44.3 μC/cm2), thus revealing the ferroelectric anisotropy. The (101) BiFeO3 films exhibited a good fatigue resistance up to 4.6 × 107 cycles, whereas the (111) BiFeO3 films proved to be vulnerable to fatigue, which is associated with the polarization switching path.