Step edge magnetoresistance of magnetite films

Summary form only given. The phenomenon of grain-boundary magnetoresistance in half-metallic oxides has attracted an intense research activity in recent years. The Curie temperature of ferromagnetic oxides, however, is too low in order to realize magnetoresistive devices operating at room temperature. There is only one notable exception: the half-metallic ferrimagnet magnetite (Fe/sub 3/O/sub 4/) with a Curie temperature of 858 K. It is shown here that grain boundaries introduced at step edges in magnetite films yield a considerable magnetoresistance.