Applied Physics Letters · 2006 · 45 citations · 16 references
Natural SciencesMaterials EngineeringMaterials ScienceElectronic MaterialsMagnetic MaterialsSemiconductor MaterialsFerromagnetic MaterialsMagnetic CharacterizationMagnetic OxidesMagnetic Properties Of SolidsMagnetism In SolidsSpintronicsBarrier LayersElectrode Interface EngineeringJunction ResistanceMagnetic Materials CharacterizationMagnetic Tunnel JunctionsSpinel StructureTunnel JunctionsTunneling Magnetoresistance
Epitaxial magnetic tunnel junctions with electrodes of spinel-structure Fe3O4 and perovskite La0.7Sr0.3MnO3 have been fabricated and characterized. Spinel barrier layers of magnetic FeGa2O4 and nominally nonmagnetic Mg2TiO4 were used to provide a good interface with the more sensitive Fe3O4 electrode interface. Junction magnetoresistances (JMRs) of up to −11% at 60K and −26% at 70K were observed for FeGa2O4 and Mg2TiO4 barrier junctions, respectively. The JMR bias dependence and junction resistance versus temperature data indicate that a majority of the junctions are dominated by elastic tunneling below about 50mV and by inelastic hopping through the barrier at higher bias.
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