Room Temperature Ferromagnetic, Anisotropic, Germanium Rich FeGe(001) Alloys

• Main Authors: Cristian M. Teodorescu, Dana G. Popescu, Nicoleta G. Apostol, Ruxandra M. Costescu, Laura E. Stoflea, George A. Lungu
• Format: Article
• Language: English
• Published: MDPI AG 2013-02-01
• Series: Materials
• Subjects: metal-semiconductor compounds; spintronics; surface magnetism; molecular beam epitaxy; X-ray photoelectron spectroscopy; magneto-optical Kerr effect
• Online Access: http://www.mdpi.com/1996-1944/6/2/612

Ferromagnetic FexGe1−x with x = 2%–9% are obtained by Fe deposition onto Ge(001) at high temperatures (500 °C). Low energy electron diffraction (LEED) investigation evidenced the preservation of the (1 × 1) surface structure of Ge(001) with Fe deposition. X-ray photoelectron spectroscopy (XPS) at Ge 3d and Fe 2p core levels evidenced strong Fe diffusion into the Ge substrate and formation of Ge-rich compounds, from FeGe3 to approximately FeGe2, depending on the amount of Fe deposited. Room temperature magneto-optical Kerr effect (MOKE) evidenced ferromagnetic ordering at room temperature, with about 0.1 Bohr magnetons per Fe atom, and also a clear uniaxial magnetic anisotropy with the in-plane  easy magnetization axis. This compound is a good candidate for promising applications in the field of semiconductor spintronics.