Electrical Detection of Spin Transport in Si Using High-quality Fe3Si/Si Schottky Tunnel Contacts

Abstract

We investigated the epitaxial growth of high-quality Fe3Si thin films on Si(111) and demonstrated electrical injection and detection of spin-polarized electrons in Si through the Fe3Si/Si Schottky-tunnel contacts. TEM observations and analyses of electron diffraction patterns revealed that precisely controlling the Fe/Si ratio during growth is important to obtain well ordered Fe3Si structures and atomically abrupt heterointerfaces at the same time. The electrical properties of Fe3Si/Si Schottky diodes with various carrier concentrations were also examined, and highly transparent tunnel contacts were demonstrated. We were able to clearly detect nonlocal spin signals in Si at 150K using Fe3Si/Si lateral four-probe devices.