Research Papers in Physics and Astronomy
Effects of germanium on the electronic transport mechanism in Co20 (Cu-xGex)80 nanogranular ribbons
Date of this Version
The dependency of giant magnetoresistance (GMR) on the nonmagnetic matrix in nanogranular Co20 (Cu1-xGex)80 ribbons was studied. When the matrix Cu is substituted with semiconductor Ge, the magnetoresistance transitioned from negative to positive at low temperatures. The positive GMR effect is closely related to the quantity of Co/Co3Ge2/Co junctionlike configurations. This result provides evidence for the competition between two types of electronic transport mechanisms in the magnetic granular ribbons: (i) electronic spin-dependent scattering, inducing a negative magnetoresistance and (ii) Coulomb blockade of the electronic tunneling, inducing a positive magnetoresistance.
Published in J. Mater. Res., Vol. 17, No. 12, Dec 2002. Copyright © 2002 Materials Research Society. Used by permission.