Magnetoresistance (MR) effect is extensively used in state-of-the-art magnetic field sensing and data storage devices. In this work, we present (a) current-perpendicular-to-plane (CPP) MR effect in multilayer graphene (MLG) grown on cobalt (Co) foil and (b) spin valve MR effect in a vertical array of multiwall carbon nanotube (MWCNT) spin valves. In part (a) strong room-temperature CPP-MR effects have been observed in as-grown MLG on Co. The origin of the MR effect lies in the graphene-Co interface and interlayer coupling between the graphene layers of MLG. In part (b) an array of vertically standing MWCNT spin valves has been synthesized in the pores of an anodic alumina template. A spin valve MR and spin relaxation length of ~ 0.28 mum have been observed at 8 K, which disappears at higher temperature. This indicates necessity of alternative designs for room temperature operation of MWCNT spin valves.
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