The interplay between
spin transport and exchange coupling profoundly affects charge transport
between conventional metals and ferromagnets. This results
in giant magnetoresistance and the spin valve
effect in multilayer thin films, phenomena of great importance for magnetic
data storage. MRSEC researchers have developed Co-Cu-Co multilayer nanowires to explore these
phenomena in nanowire geometries.
Element-sensitive
scanning transmission electron microscopy reveals the composition of these
multilayer nanowires. The thinnest Cu
spacers produce a sizable 12% GMR at room temperature, consistent with
interlayer exchange coupling. This coupling weakens with increasing Cu
thickness, until a spin valve results. The evolution between these regimes
provides new insights into spin diffusion in restricted geometries.
