Pentacene Thin Films On Ferromagnetic Oxide: Growth Mechanism And Spintronic Devices

We investigated the growth mechanism of pentacene thin films on La0.7Sr0.3MnO3. A diffusion limited, thermally activated growth was found. Pentacene molecules formed flat islands that were a few microns in size and whose growth during deposition showed a strong anisotropy. We extracted a nucleation energy of 0.65 +/- 0.05 eV and a diffusion barrier energy of 0.7 +/- 0.2 eV, We also estimated a critical nucleus size of three molecules. We show that vertical pentacene-based spintronic devices with La0.7Sr0.3MnO3 and Co electrodes demonstrated magnetoresistive effects up to room temperature. We also propose a route for pentacene-based spintronic devices improvement. (C) 2014 AIP Publishing LLC.