Magnetization reversal process in TbCo-biased spin valves

The magnetization reversal processes in the free and the pinned layers of TbCo-biased spin valves have been studied in a highly modified transmission electron microscope. Reversal of the free layer in the presence of a field antiparallel to the biasing direction proceeds by a complex domain process with 360 degrees walls forming frequently. In the presence of substantially higher fields, the pinned layer reverses by creep of highly irregular walls through the structure. By studying image grey levels, an estimate of the average orientation of the induction vector in the TbCo layer is made. (C) 1996 American Institute of Physics.