Tunneling transport properties for metal-oxide-semiconductor diode consisting of ferromagnetic ZnMnO nanocrystals

Spin-dependent tunneling properties for the metal-semiconductor-oxide diode which was fabricated using ferromagnetic ZnMnO nanocrystals and Ti-Co ferromagnet were investigated. The diode revealed current oscillation packets after tunneling-on, and the peak-to-valley current ratio of the packets showed to be dependent on the temperature-dependent magnetization of the nanocrystals; i.e., the peak-to-valley current ratio of the packets was increased with decreasing the temperature. This result is ascribed to the increased conductance fluctuation due to the increased repulsion probability between spin-polarized and unpolarized carriers because the spin-polarized carriers which are supplied from Ti-Co and are to be injected into n+ -Si are transferred through the nanocrystals.