MFM/SEMPA Comparison

The Magnetic Force Microscope (MFM) has recently become a very popular tool for characterizing magnetic microstructure. Cost, simplicity, and the ability to look through nonmagnetic overlayers with minimum sample preparation are all reasons why MFMs are routinely used by industry for magnetic materials characterization. A major drawback of the MFM is that the rather complicated interaction between the the magnetic tip and surface makes quantitative interpretation of the MFM images difficult. On the other hand, SEMPA images are directly proportional to the magnitude and direction of the magnetization. We are therefore currently measuring various magnetic materials with both the MFM and SEMPA in order to first compare the two techniques, and second to evaluate various methods of obtaining quantitative magnetization information from the MFM images.

A preliminary comparison between the two techniques is shown in the figure. The images are from different regions on a high density hard disk. In future work we plan to collaborate with Maxtor, Inc. and the NIST Electromagnetics Division to make special patterned media samples so that exactly the same regions may be imaged and compared.

John Unguris
Robert J. Celotta
Daniel T. Pierce

Andrew Gavrin - Indiana University - Purdue University at Indiana
Michael Kelley - NIST
David Tulchinsky - Naval Research Laboratory

Paul Rice - NIST Boulder
John Moreland - NIST Boulder
Quock Ng - Maxtor, Inc.

Supported in part by the Office of Naval Research

Online: May 1996
Last Updated: February 2008

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