High‐resolution magnetic imaging by force microscopy (invited) (abstract)

Abstract

The scanning tunneling microscope is a unique tool which is capable of imaging conducting and semiconducting surfaces with atomic resolution. More recently, the atomic force microscope has been able to extend the class of objects that can be imaged with atomic resolution to include insulators. The work in this paper is concerned with a modified version of an atomic force microscope—the laser heterodyne force probe— which is capable of measuring force gradients (magnetic and other) down to 10−6 N/m and forces down to 10−12 N with high spatial resolution. Magnetic images are obtained by measuring the forces on a magnetized iron tip as the tip is rastered across the sample to be imaged and displaying the result on a computer display. The forces and force gradients are measured through a change in oscillation amplitude of the “vibrating reed” tip when the tip is driven at or near its fundamental resonance. Images of both dynamic fields from a thin film magnetic recording head and static fields from written domains have been obtained with 1000‐Å resolution. With further work we believe it should be possible to improve this resolution to around 100 Å. © 1988, American Institute of Physics. All rights reserved.