Published online by Cambridge University Press: 15 February 2011
Tunneling stabilized magnetic force microscopy (TSMFM) is a variant of scanning tunneling microscopy (STM) where the usual rigid STM tip is replaced with a flexible magnetic tip. This method contrasts with other magnetic force microscopes based on optical or capacitive detection of cantilever deflection due to magnetic forces. Instead, the position of the flexible tunneling tip depends on both topography and magnetic forces acting on the end of the tip. The z-motion of the piezoelectric translator flexes the tip to balance the magnetic force so that the end of the tip remains a fixed tunneling distance from the sample surface. We present a review of some TSMFM images showing the recorded bit patterns on hard disk, floppy disk, and tape surfaces. The images were taken in air using STM tips made from free-standing Fe and Ni films about 1 μm thick. The image resolution of TSMFM is routinely submicrometer. We conclude that this simple modification of STM will be a valuable diagnostic tool in the magnetic recording industry.