Cu$_{1-x}$Fe$_x$O: Hopping Transport And Ferromagnetism

Abstract

Single phase, sol-gel prepared Cu1-xFexO (0<x<0.125) are characterized in terms of structural, electronic and magnetic properties. Using dielectric and magnetic studies we investigate the coupling of electron and spin. The electrical conductivities and activation energies are studied with increasing Fe content. Modeling of experimental conductivity data emphasizes on a single hopping mechanism for all samples except x=0.125, which have two activation energies. Hole doping is confirmed from Hall effect [1] and by confirming a majority Fe3+ substitution of Cu2+ in CuO from XPS studies. Such a substitution results in stabilized ferromagnetism. Fe substitution introduces variation in coercivity as an intrinsic magnetic property in Fe-doped CuO, and not as a secondary impurity phase.