Magnetic force microscopy image restoration technique for removing tip dependence

Abstract

Quantitative interpretation of a magnetic force microscopy (MFM) image usually requires detailed knowledge of the magnetization configuration of the sensing tip. Here, we demonstrated a technique that converts the obtained raw MFM image into the magnetic pole density distribution without explicitly knowing the tip magnetization orientation. By creating an approximate point source of magnetic poles in the same sample imaged, the impulse response function of the MFM tip is obtained for deconvolution of a raw image in the Fourier space. Experimental demonstrations with various tip magnetization orientations were performed on recorded magnetic transitions in a thin film longitudinal medium.

The role of MFM signal in mark size measurement in probe-based magnetic recording on CoNi/Pt multilayers

“…Regarding the effect of the finite size of the actual MFM tip, it is a complicated problem. Some peer researchers applied a restoration technique to remove the tip dependence of the MFM image: Zhu et al [13] models the tip as a half sphere, and Candocia et al [14] models the tip as a cube. Their results show that the modeling of the finite tip size reduces the resolution of the MFM image, but does not hurt the mark size measurement.…”

A method for the calibration of magnetic force microscopy tips

“…The obtained transfer functions were used to deconvolve a measurement of a hard disk track to obtain the in-plane magnetization pattern. Chang et al 5 and Zhu et al 7 used an impulse response function that is defined as the MFM response to a magnetic point charge at the sample surface. They used a nanostructured magnetic particle and partially erased bit transition in a hard disk track, respectively, as an approximation for this point charge.…”

“…23 and 22 and for the reconstruction of MFM data in Ref. 7. Here, the use of such filters is omitted for the sake of simplicity.…”

“…2 The other group takes this feature-size dependence into account by determining the relative strength with which magnetic features of different wavelengths are imaged. [4][5][6][7] However, in papers describing this type of method, no absolute relationship between MFM measurement and magnetic quantity is given.…”

Reconstruction of in-plane magnetization distributions from magnetic force microscope images

“…Considerable progresses has been made in developing transformation methods from MFM signal to magnetic field or surface charges. [1][2][3][4][5] For these analyses, the necessary inputs are the accurate information about the magnetization distribution of the MFM tip, which may be different from tip to tip, and the force gradient signal which can be obtained by transforming the measured phase signal of the MFM. In addition, some work has focused on quantifying phase-force gradient function to measure the effective moment of the tip.…”