Mean free path effects on the current perpendicular to the plane magnetoresistance of magnetic multilayers
We have carried out an experimental and theoretical study of the magnetoresistance MR(H) in the CPP (current perpendicular to the planes) mode for two types of magnetic multilayers that differ only in the ordering of the magnetic layers: [Co(10 A)/Cu(200 A)/Co(60 A)/Cu(200 A)](N) and [Co(10 A)/Cu(200 A)](N)[Co(60 A)/Cu(200 A)](N). The series resistor model predicts that in the CPP mode MR(H) is independent of the ordering of the layers. Nevertheless, the measured MR(H) curves were found to be completely different for the two cases. Calculations based on a realistic band structure and the Kubo formula show that the results are a consequence of a long mean free path.
Bozec
D
Department of Physics and Astronomy, E. C. Stoner Laboratory, University of Leeds, Leeds LS2 9JT, United Kingdom.
Howson
MA
Hickey
BJ
Shatz
S
Wiser
N
Tsymbal
EY
Pettifor
DG