Introduction to Nanotechnology

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7.6. GIANT AND COLOSSAL MAGNETORESISTANCE 183
B [10-'T]
Figure 7.16. Dependence of the electrical resistance R(B), relative to its value R(0) in zero field,
of a layered irowchromium system on a magnetic field B applied parallel to the surface of the
layers. [Adapted from R. E. Camley, J. Phys. Condens. Matter 5, 3727 (1993).]
nanoparticles parallel to the direction of the field, which reduces the resistance. The
magnitude of the effect of the applied magnetic field on the resistance increases with
the strength of the magnetic field and as the size of the magnetic nanoparticles
decreases. Figure 7.18 shows a representative measurement at l00K of a film
0 2 4 6 8 10 12 14 16 18 20
THICKNESS OF Fe LAYER (nm)
Figure 7.17. Dependence of the change of magnetoresistance AR on the thickness of the iron
magnetic layer in a constant DC magnetic field for the F 4 r layered system. [Adapted from
R. E. Camley, J. Phys. Condens. Matter 5, 3727 (1993).]