AB-INITIO MAGNETORESISTANCE IN MAGNETIC DOMAIN-WALLS

The effect of magnetic domain walls on the resistance of a ferromagnet is an open problem in the sense that a consistent picture concerning the magnitude and the microscopic origin is still lacking. In this pal ?er He present ab initio calculations of the specular transmission thr ough domain walls in nickel, cobalt and iron. We show that for domain walls with realistic thicknesses, the effect of the domain wall on the conductance (as measured in a point-contact geometry) is indeed small but non-vanishing, in agreement with the recent experiments of Gregg et al. [Phys. Rev. Lett, 77 (1996) 1580]. The change in the conductanc e due to the domain wall is entirely attributable to the change in the electronic band structure of the ferromagnet brought about by the mag netization rotation. For a given total rotation (e.g, a 180 wall, a st rong increase with decreasing wall thickness is predicted. (C) 1996 El sevier Science B.V, All rights reserved.