IN-SITU TRANSMISSION ELECTRON-MICROSCOPY STUDIES OF THE MAGNETIZATIONREVERSAL MECHANISM IN INFORMATION-STORAGE MATERIALS

The Foucault and Fresnel modes of Lorentz microscopy, together with a quantitative magnetization mapping technique, summed image differentia l phase-contrast imaging, were used to study the magnetization reversa l mechanism of the sense layer in spin-valve structures exhibiting the giant magnetoresistance effect. In addition to studies of sheet film, lithographically defined spin-valve elements were investigated. A cur rent can be passed through the element during magnetizing so that the effect of the applied current on the giant magnetoresistance and magne tization reversal mechanism can be studied. Results are presented for a number of different spin-valve structures.