Magnetoresistance in bicrystal Fe3O4 thin films

An epitaxial magnetite (Fe3O4) film has been deposited by the pulsed laser deposition (PLD) technique on a bicrystal substrate. Magnetoresistance measurements on patterned stripes (width=20 μm) across the bicrystal grain boundary have not revealed a distinguishable grain boundary contribution. Post-annealing of the film has a strong influence on the relaxation degree of the film and on the density of antiphase boundaries. Magnetotransport measurements of the micrometer-patterned annealed film show significantly enlarged high-field magnetoresistance values at low temperatures.