IN-SITU STUDIES OF THE PROPERTIES OF MICROMETER-SIZED MAGNETIC ELEMENTS BY COHERENT FOUCAULT IMAGING

Coherent Foucault (CF) imaging has been implemented in a transmission electron microscope to obtain magnetic interferograms of micrometre-si zed permalloy elements fabricated by electron beam-lithographic and ev aporation techniques. The interferograms provide a quantitative descri ption of the distribution of flux throughout the elements. We have obs erved how this changes under the influence of applied magnetic field a nd temperature variation. Results are presented for rectangular elemen ts of thickness 30 nm. From the magnetizing experiments, details of th e transformation between solenoidal and non-solenoidal magnetization d istributions are revealed, whereas the heating experiments show how do main structures are modified as the temperature of the element is incr eased from room temperature to beyond the Curie point.