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First Principles Based Solution to the Boltzmann Transport Equation for Co/Cu/Co Spin Valves

Published online by Cambridge University Press:  14 March 2011

J.M. Maclaren
Affiliation:
Department of Physics, Tulane University, New Orleans, Louisiana 70118 Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148
L. Malkinski
Affiliation:
Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148
J.Q. Wang
Affiliation:
Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148
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Abstract

We present the results of a first principles based semi-classical study of electronic transport in Co/C/u/Co spin valves. The model is parameterized using Bloch states obtained from local spin-density electronic structure calculations and lifetimes appropriate to sputtered films. The approach is used to study the variation in giant magnetoresistance (GMR) with the individual layer thicknesses. Using values for the lifetimes for electrons in the Co and Cu layers that reproduce the resistivities of sputtered films, we are able to rationalize the variation in the current in the plane (CIP) GMR in a set of Co/Cu/Co spin valves produced under similar conditions. Important contributions to the GMR come from two sources, a channeling effect in the Cu which is a direct result of the different sized Fermi spheres for majority Cu and Co electrons, and from within a region in the Co layers within about one to two mean free paths of the interface. Unlike the CIP GMR, values for the current perpendicular to the plane (CPP) GMR are much larger and much less sensitive the variations in the individual layer thicknesses.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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References

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