Research Papers in Physics and Astronomy


Date of this Version



Published by American Institute of Physics. Appl. Phys. Lett. 80, 1779-1781 (2002). ©2002 American Institute of Physics. Permission to use.


We report a transition of the giant magnetoresistance (GMR) behavior in nanocrystalline Co20 (Cu1-xGex)80 ribbons from negative to positive, as the semiconductor Ge substitutes for the Cu matrix. The growth of the hexagonal Co3Ge2 compound leads to a change of the physical origin of the GMR. The normal spin-dependent transport behavior in the CoCu granular system evolves into Coulomb blockade behavior of electronic tunneling in ribbons with a Co/Co3Ge2/Co junctionlike configuration.

Included in

Physics Commons