Absolute field strength determination of magnetic force microscope tip stray fields

Quantitative analysis of magnetic force microscope (MFM) images is only possible if the magnetic state of the sensing tip is known. In this paper we describe a method which is used to characterise the stray field produced by an MFM tip. The method utilises Lorentz microscopy techniques and tomographic field reconstruction algorithms. A specially constructed calibration specimen enables measurement of the absolute values of the tip stray field to be made.