The barrier quality and conduction mechanisms in ferromagnet-insulator- ferromagnet (FIF) junctions are studied by fabricating adjacent ferromagnet-insulator-superconductor (FIS) junctions, using the same barrier and top electrode in both junctions. Transport measurements on the FIS junctions provide information about the transport processes in the FIF junctions. The FIS junctions have a large zero-bias conductance (ZBC) that varies with barrier thickness, in part due to ballistic channels in parallel with the tunnel barrier. As the ZBC increases, the magnetoresistance (MR) in the FIF junctions decreases, implying that these ballistic channels are not magnetoresistive and that their presence reduces the total MR in the FIF junctions.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)