Effects of Long-Range Tip-Sample Interaction on Magnetic Force Imaging: A Comparative Study Between Bimorph Driven System and Electrostatic Force Modulation

Magnetic force microscopy (MFM) using electrostatic force modulation has been designed and developed to avoid the drawbacks of the bimorph driven system. The bimorph driven system has poor frequency response and overlap of the topographic features on magnetic structures of the MFM images. In the electrostatic force modulation system, the amplitude increases in the noncontact regime as the tip approaches due to the capacitive coupling between tip and sample. MFM using electrostatic force modulation has been applied to observe maze-like stripe domain structures on a CoCr film. The contrast mechanism and imaging stability of MFM using electrostatic force modulation are discussed by investigating the force distance curves obtained in two magnetic domain regions.