THE DIRECT OBSERVATION OF MAGNETISATION REVERSAL IN FILMS OF INTEREST FOR HIGH DENSITY INFORMATION STORAGE

Lorentz electron microscopy in a highly modified transmission electron microscope has been used to study the magnetisation reversal process in films of interest as magneto-optic storage media. Domain structures, mainly in CoNi/Pt multilayers, have been observed under a range of applied field conditions. Whilst domain propagation under increasing fields and the approach to saturation have both been investigated, the focus has been on the early stages of domain growth where time-dependent effects are prominent. Close agreement between experimental observations and micromagnetic modelling has been achieved allowing values of the domain wall energy to be extracted.