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

We report the multiferroic properties of epitaxially (100) oriented BiMnO3 thin film on (100) LaAlO3 substrate and preferentially (111) oriented BiMnO3 thin film on (111) Pt/TiO2/SiO2/Si substrate. Nano-size bits of ferroelectric polarization on the BiMnO3 thin film on (111) Pt/TiO2/SiO2/Si substrate can be easily written and read by Kelvin force microscope (KFM). We found that, for the preferentially (111) oriented BiMnO3 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 BiMnO3 thin film is a potential candidate for the high-density data storage device based on KFM.