In situ transmission electron microscope studies of information storage materials

A thin-layered magnetic film of Co/Cu/Co/MnFe exhibiting giant magnetoresistance (GMR) as magnetic sensors were developed for use in information storage technology with fewer layers such as spin-valve (SV) structures for magnetoresistive read heads. The GMR effect in SVs was smaller, but the resistance varies faster with applied magnetic field. The magnetic field in such structures can be more accurately controlled than in multilayers because the magnetic moments in different layers are uncoupled. Exploitation of theses materials depends on understanding the effects of microstructure and of local inhomogeneities, on the magnetizatiton configuration of the SV and their response to an applied magnetic field.