Writing polarization bits on the multiferroic BiMnO3 thin film using Kelvin probe force microscope

We report the multiferroic properties of epitaxially (100) oriented ${\mathrm{BiMnO}}_3$ thin film on (100) ${\mathrm{LaAlO}}_3$ substrate and preferentially (111) oriented ${\mathrm{BiMnO}}_3$ thin film on (111) ${\mathrm{Pt/TiO}}_2/{\mathrm{SiO}}_2/\mathrm{Si}$ substrate. Nano-size bits of ferroelectric polarization on the ${\mathrm{BiMnO}}_3$ thin film on (111) ${\mathrm{Pt/TiO}}_2/{\mathrm{SiO}}_2/\mathrm{Si}$ substrate can be easily written and read by Kelvin force microscope (KFM). We found that, for the preferentially (111) oriented ${\mathrm{BiMnO}}_3$ thin film, only ferroelectric polarization has been induced at the low writing biases, which makes the writing and reading process simple. This suggests that the preferentially oriented ${\mathrm{BiMnO}}_3$ thin film is a potential candidate for the high-density data storage device based on KFM.