Off-Axis Electron Holography of Single Ferromagnetic Nanowires

Off-axis electron holography has been applied to study the remanent magnetization state of single ferromagnetic Co93Cu7 nanowires a few micrometer in length and a typical radius of 40nm. Because the objective lens of the electron microscope has to be switched off, the spatial resolution of the reconstructed phase images is presently limited to approximately 70nm. The magnetization reversal of an individual nanowire has been followed by observing a series of remanent states, obtained ex situ by applying different external magnetic field sweeps parallel to the nanowire axis. The relation between misoriented crystal grains and nonuniform magnetization states has been studied by the combination of electron holography and conventional transmission electron microscopy.