Fabrication Method, Ferromagnetic Resonance Spectroscopy and Spintronics Devices Based on the Organic-Based Ferrimagnet Vanadium Tetracyanoethylene

摘要

Organic-based magnetic materials have been used for spintronic device applications as electrodes of spin aligned carriers and spin-pumping substrates. Their advantages over more traditional inorganic magnets include reduced magnetic damping and lower fabrication costs. Vanadium tetracyanoethylene, V[TCNE](x) (x approximate to 2), is an organic-based ferrimagnet with an above room-temperature magnetic order temperature (T-c approximate to 400 K). V[TCNE](x) has deposition flexibility and can be grown on a variety of substrates via low-temperature chemical vapor deposition (CVD). A systematic study of V[TCNE](x) thin-film CVD parameters to achieve optimal film quality, reproducibility, and excellent magnetic properties is reported. This is assessed by broadband ferromagnetic resonance (FMR) that shows most narrow linewidth of approximate to 1.5 Gauss and an extremely low Gilbert damping coefficient. The neat V[TCNE](x) films are shown to be efficient spin injectors via spin pumping into an adjacent platinum layer. Also, under an optimized FMR linewidth, the V[TCNE](x) films exhibit Fano-type resonance with a continuum broadband absorption in the microwave range, which can be readily tuned by the microwave frequency.