3D magnetic characterization of nanocrystalline cobalt thin films by combined magnetic force and Lorentz microscopy

Abstract

Thin films of cobalt and cobalt-based compounds are recently popular for magnetic recording media because of their high recording density and great magnetic properties. Many techniques exist to image magnetic structures in thin films, nevertheless, none of them can furnish complete information about the magnetic details. In the present work the combined use of the information obtainable with Lorentz microscopy, performed in a transmission electron microscope (TEM), and of an atomic force microscope (AFM) working in the magnetic mode (MFM, magnetic force microscopy), both performed on the same specimen area, enabled, in a easy way, the study of the 3D magnetic structure of domains, of single cross-ties, the location of Bloch lines within a domain wall and the magnetic structure of magnetisation ripples. The 3D magnetic structure and contrast of nanocrystalline thin films of cobalt (100 nm thick), prepared by evaporation in high vacuum, were investigated at a spatial resolution of tens of nanometers.