SPIN-DEPENDENT SCATTERING AND GIANT MAGNETORESISTANCE

We consider the origins of the spin-dependent scattering which is beli eved to he responsible for the giant magnetoresistance effect. We argu e on the basis of first-principles calculations of the electronic stru cture, magnetic moments, and electrical resistivities that this spin-d ependent scattering originates largely from the tendency of spin-depen dent atomic potentials to 'match' in one of the spin channels of magne tic alloys or multilayers. We also argue that the matched channel will tend to have a lower density of stares at the Fermi energy. Both of t hese effects will contribute to the GMR. We argue that there is the po tential for a very large GMR in an ideal system, but that spin-indepen dent scattering possibly coming from misaligned spins near the interfa ces prevents its observation.