Spin polarization and electronic structure of ferromagnetic Mn₅Ge₃ epilayers

Abstract

Germanium‐based alloys hold great promise for future spintronics applications, due to their potential for integration with conventional Si‐based electronics. High‐quality single phase Mn5Ge3(0001) films, grown by solid‐phase epitaxy on Ge(111) and GaAs(111), exhibit strong ferromagnetism up to the Curie temperature TC ∼ 296 K. Point Contact Andreev Reflection (PCAR) measurements on Mn5Ge3 epilayers reveal a spin‐polarization P = 42 ± 5% for both substrates. We also calculate the spin polarization of bulk Mn5Ge3 in the diffusive and ballistic regimes using density‐functional theory (DFT). The measured spin polarization exceeds the theoretical estimates of PDFT = 35 ± 5% and 10 ± 5% for the diffusive and ballistic limits, respectively. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Epitaxial growth of Mn5Ge3/Ge(111) heterostructures for spin injection

“…However, this compound presents very interesting properties: it is a stable phase in the MnGe phase diagram, it is intermetallic and ferromagnetic up to room temperature. Theoretical calculations predicted a high spin-injection efficiency along the c axis of Mn 5 Ge 3 [13] and a spin polarization up to 42% [14] has been demonstrated. Furthermore, Mn 5 Ge 3 thin films have been shown to epitaxially grow on Ge(111) substrates [15,16], allowing a direct injection of spin-polarized current into a semiconductor.…”

Ferromagnetic resonance and magnetic damping in C-doped Mn5Ge3

“…Mn 5 Ge 3 shows ferromagnetism with a Curie temperature (T c ) around room temperature [5] and an important spin polarization (up to 42%) [6,7]. The Mn 5 Ge 3 hexagonal cell contains 10 Mn atoms which are arranged in two different sublattices (Mn I and Mn II ) due to different coordination.…”

Non-collinear magnetic states of Mn5Ge3 compound

“…Among them, Mn 5 Ge 3 shows ferromagnetism with a Curie temperature of 300 K [6][7][8]. Recently, ferromagnetic Mn 5 Ge 3 thin films grown epitaxially on Ge(111) by means of solid-phase epitaxy [8,9] exhibited metallic conductivity and strong ferromagnetism up to 296 K, thus holding out promise for use in spin injection.…”