Spin Polarized Scanning Tunneling Microscopy of Alq3 on Cr(001)*

The field of organic spitronics has been strongly motivated in recent years by the observation of giant magnetoresistive effects in tris-(8-hydroxyquinoline) aluminum (Alq3) films and nanostructures. It is crucial to understand the spin- dependent electronic structure at metal-Alq3 interfaces. We have carried out spin polarized scanning tunneling microscopy to measure the local density of electronic states for submonolayer films of Alq3 grown on the layered anitferromagnetic Cr(001) surface. We report an energy-dependent tunneling conductance asymmetry for single molecules adsorbed on differently magnetized (001) terraces and discuss its connection with metal-molecule hybridization and magnetoresistive effects in Alq3 spintronic devices.