ANISOTROPIC MAGNETORESISTANCE AND PLANAR HALL-EFFECT IN MAGNETIC METAL-INSULATOR COMPOSITE FILMS

We studied anisotropic magnetoresistivity (AMR) and planar Hall effect of granular Ni-rich NiFe-SiO2 and Fe-SiO2 films for various metallic volume fraction. Planar Hall resistivity was found to be the same as t he magnetoresistivity (MR) difference between the longitudinal and the transverse geometry. As metallic volume fraction decreases, we found that the MR evolves from the AMR domination in the metallic conduction region, through an intermediate conduction region with mixed AMR and negative MR behavior, to the isotropic negative MR in the tunneling co nduction region. Plausible explanations to this complicated evolution are discussed. (C) 1997 American Institute of Physics.