In situ experiments in a Lorentz transmission-electron microscope have been performed on spin-valve elements through which a current is being applied. The ability to simultaneously measure the resistance and observe the domain structure of the element has allowed us to correlate magnetoresistance with the angle between the magnetization directions in the ferromagnetic layers. The angles have been obtained from summed image differential-phase-contrast images of the domains. A model is proposed to calculate the resulting magnetoresistance. The calculated data are in good agreement with the experimental magnetoresistance measured during observation of the magnetization reversal mechanism.

• Received 18 March 1998

DOI:https://doi.org/10.1103/PhysRevB.58.R591