We have studied the magnetotransport properties of a new metallic granular Co-Ag system. The spin-dependent electron scattering is revealed in the forms of a giant magnetoresistance and an extraordinary Hall effect, both of which are found to be strongly dependent on the Co particle size and the electron mean free path. The experimental correlation ${\mathrm{\rho }}_{\mathit{x}\mathit{y}}$∝${\mathrm{\rho }}_{\mathit{x}\mathit{x}}^{3.7}$ uncovered is unexpected from existing theories. Interfacial scatterings of intermediate range are required in order to account for the anomalous magnetotransport in this magnetic granular system.

• Received 11 August 1992

DOI:https://doi.org/10.1103/PhysRevLett.69.3220