1 research outputs found
Room-Temperature Spin Filtering in Metallic Ferromagnet–Multilayer Graphene–Ferromagnet Junctions
We
report room-temperature negative magnetoresistance in ferromagnet–graphene–ferromagnet
(FM|Gr|FM) junctions with minority spin polarization exceeding 80%,
consistent with predictions of strong minority spin filtering. We
fabricated arrays of such junctions <i>via</i> chemical
vapor deposition of multilayer graphene on lattice-matched single-crystal
NiFe(111) films and standard photolithographic patterning and etching
techniques. The junctions exhibit metallic transport behavior, low
resistance, and the negative magnetoresistance characteristic of a
minority spin filter interface throughout the temperature range 10
to 300 K. We develop a device model to incorporate the predicted spin
filtering by explicitly treating a metallic minority spin channel
with spin current conversion and a tunnel barrier majority spin channel
and extract spin polarization of at least 80% in the graphene layer
in our structures. The junctions also show antiferromagnetic coupling,
consistent with several recent predictions. The methods and findings
are relevant to fast-readout low-power magnetic random access memory
technology, spin logic devices, and low-power magnetic field sensors