Magnetotransport properties of oxidized iron thin films

Abstract

We report results of electrical resistivity, Hall effect, and anisotropic magnetoresistance (AMR) measurements performed on thin films (~80 nm) of naturally oxidized iron in the 5 to 300 K temperature range, and in magnetic fields up to 5 T. The films were grown at low temperatures. We find that the resistivity, coercive field, as well as the magnetoresistance of the films are affected by growth conditions, particularly by the substrate temperature which controls the size and shape of crystalline grains. We used AMR as a probe for magnetization reversal studies in our films. We find that the coercive fields vary as as in systems of weakly interacting ensembles of magnetic nanoparticles even though dipole-dipole interactions may well play a significant role.