Quantitative magnetic field measurements with the magnetic force microscope

Abstract

We have developed a technique to quantitatively image the magnetic field above a magnetic specimen using a modified magnetic force microscope (MFM). The technique depends on the nonlinear response of a magnetically soft MFM tip to the sample field and to an externally applied field, similar in principle to fluxgate magnetometry. We demonstrate the technique with high resolution, quantitative images of the magnetic field above a sample of longitudinal recording media. The magnetic field resolution is on the order of 1 Oe, with sub-100 nm spatial resolution comparable to standard MFM techniques.

Stray fields above artificial magnetic in-plane domains

“…For comparison, the out-of-plane component of the MFL in a longitudinal recording media (made of 20 nm CoCr) was reported to be about 5.2 kA/m at a distance of 100 nm from the surface and at the center of the domain wall [30]. Recently, an estimate for the magnetic fields coupling two perpendicular-to-plane domains of Co in a [FeNi 2 nm /Au 1.5 nm /Co 0.6 nm /Au 1.5 nm ] 15 multilayer was deduced from its magnetoresistive characteristics to be of the order of 100 kA/m [31].…”

Quantification of magnetic force microscopy images using combined electrostatic and magnetostatic imaging

“…Previous approaches have involved the imaging of a standardized system, such as a metal strip 3,4 or single-crystal surfaces 5 or the usage of sophisticated methods to measure the magnetic moment of the probe and compare the acquired data with various models for the probe. 6,7 There are, however, no methods that prescribe a self-contained calibration procedure of both the probe's mechanical and magnetic characteristics by utilizing only the measurements of the instrument itself. In this work, we propose a straightforward method for estimating K p and m z , thereby allowing a direct quantification of the MFM response.…”

Investigation of the current path of Pb(Zr,Ti)O3 thin films using an atomic force microscope with simultaneous current measurement

“…This technique has also the ability to evaluate electrical, 14,15 optical, 16 and magnetic 17,18 properties microscopically. Recently, investigations on the conduction mechanism of organic positive temperature coefficient of resistance compounds using the SPM technique have also been reported.…”