ABSOLUTE MAGNETOMETRY OF THIN COBALT FILMS AND CO CU MULTILAYER STRUCTURES AT NANOMETER SPATIAL-RESOLUTION/

The absolute measurement of magnetization in thin magnetic specimens a t nanometer spatial resolution has been made possible by implementing two off-axis holography modes in a scanning transmission electron micr oscope (STEM). The absolute mode of STEM holography displays a linear change in phase difference for regions with constant magnetization and the slope determines the absolute value of magnetization in the speci men. The differential mode of STEM holography displays a constant valu e of phase difference for regions with constant magnetization, which s implifies the identification of magnetic structures in the specimen an d the determination of domain wall profiles. Taking into account the h igh spatial resolution of a STEM instrument, STEM holography provides a valuable tool for quantitative investigations of magnetic structures at the nanometer level.