  Organic semiconductors find increasing importance in spin transport devices
due to the modulation and control of their properties through chemical
synthetic versatility. The organic materials are used as interlayers between
two ferromagnet (FM) electrodes in organic spin valves (OSV), as well as for
magnetic spin manipulation of metal-organic complexes at the molecular level.
In the latter, specifically, the substrate-induced magnetic switching in a
paramagnetic molecule has been evoked extensively, but studied by delicate
surface spectroscopies. Here we present evidence of the substantial magnetic
switching in a nanosized thin film of the paramagnetic molecule,
tris(8-hydroxyquinoline)iron(III) (Feq3) deposited on a FM substrate, using the
magnetoresistance response of electrical spin-injection in an OSV structure,
and the inverse-spin-Hall effect induced by state-of-art pulsed microwave
spin-pumping. We show that interfacial spin control at the molecular level may
lead to a macroscopic organic spin transport device, thus, bridging the gap
between organic spintronics and molecular spintronics.
