On the construction of an Fe3O4-based all-oxide spin valve

The progress made in constructing an all-oxide spin valve based on the intrinsic, fully spin-polarized electron transport in Fe3O4 is discussed. Two possible oxidic spacer layers, MgO and Mn3O4, have been investigated. Interlayer coupling studies indicate that MgO is the more suitable spacer layer of the two. Thus far a limited magnetoresistive effect less than or equal to 0.4% is found in the all oxide, Fe3O4-based, spin-valves which we have made. Possible causes for this low magnetoresistive effect are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.