Galvanomagnetic measurements in Fe₃O₄

Abstract

Resistance, DC Hall effect and transverse magnetoresistance (TMR) measurements were attempted on a synthetic monocrystal of magnetite over the range 60-280K in fields up to 47*105 A m-1. The conductivity below Tv is described by a model which incorporates the temperature-dependent overlap of the wavefunctions. Systematic tendencies in the Hall and TMR effects above Tv suggest two components: one that is sensitive to the relative orientation of current flow and the domain walls and the other that arises from an interaction at the Fe ions. The former makes the current distribution very sensitive to the magnetic state and so accounts for some improbable results reported previously for the range below Tv.