Magnetic force microscopy imaging of in-plane magnetic field gradient using transient oscillation

作者:Saito H*; Egawa G; Ishio S; Li Guoqing
来源:Journal of Applied Physics, 2008, 103(7): 07D921.
DOI:10.1063/1.2844709

摘要

A new imaging method of the in-plane magnetic field gradient using the transient oscillation of a magnetic force microscopy (MFM) tip was demonstrated by detecting the frequency shift of a MFM tip which was driven at a constant frequency. The gradient of the in-plane magnetic field along the in-plane scanning direction was measured by using a MFM tip which was magnetized in the direction normal to the sample plane. The image contrast of the in-plane magnetic field gradients reversed by scanning the same line in opposite direction. Two-dimensional vector imaging was possible by using this method together with the conventional phase detection method which detects the perpendicular magnetic field gradients. From theoretical analysis, the signal of the present method was thought to correspond to the in-plane magnetic field gradient and the present method was expected to have a higher spatial resolution because the higher-order field gradient was detected by the presented method compared to the conventional phase detection method.