Mn5Ge3 films grown on Ge(1 1 1)-c(2 × 8)

P. de Padova (1) , J.-M. Mariot (2) , Luc Favre (3) , Isabelle Berbezier (3) , B. Olivieri (4) , P. Perfetti (1) , C. Quaresima (1) , C. Ottaviani (1) , A. Taleb-Ibrahimi (5) , P. Le Fèvre (5) , F. Bertran (5) , O. Heckmann (6) , M.C. Richter (6) , W. Ndiaye (6) , F. d'Orazio (7) , F. Lucari (7) , C.M. Cacho (8) , K. Hricovini (6)

1 ISM - Instituto di Struttura della Materia
2 LCPMR - Laboratoire de Chimie Physique - Matière et Rayonnement
3 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
4 ISAC - CNR Institute of Atmospheric Sciences and Climate
5 SSOLEIL - Synchrotron SOLEIL
6 LPMS - Laboratoire de Physique des Matériaux et des Surfaces
7 Dipartimento di Fisica [L'Aquila]
8 CLF - Central Laser Facility

An investigation of the structural, magnetic and electronic properties of ≈ 3 nm thick Mn5Ge3 films epitaxially grown on a Ge(1 1 1)-c(2 × 8) reconstructed surface is reported. High resolution transmission electron microscopy and selected area electron diffraction give evidence of 2.2% in-plane compressive strain between the Mn5Ge3 film and the Ge substrate. Magnetooptical Kerr effect measurements show that the films are ferromagnetic with a Curie temperature of ≈ 325 K. The analysis of Ge 3d core level photoelectron spectra of the Mn5Ge3 films allows determining an upper limit of 76 meV for the Ge 3d5/2 core-hole lifetime broadening. The Ge 3d3/2 core-hole lifetime broadening is found to be 15 meV larger than that of the Ge 3d5/2 core hole, because of the existence of a Coster–Kronig decay channel due to the metallic character of Mn5Ge3.

Mots clés: Electron microscopy; Metal-semiconductor magnetic thin film structures; Mn5Ge3; Synchrotron radiation photoelectron spectroscopy; Transmission high-energy electron diffraction

Domaines: Matière Condensée [cond-mat]

P. de Padova, J.-M. Mariot, Luc Favre, Isabelle Berbezier, B. Olivieri, et al.. Mn5Ge3 films grown on Ge(1 1 1)-c(2 × 8). Surface Science : A Journal Devoted to the Physics and Chemistry of Interfaces, 2011, 605 (5–6), pp.638--643. ⟨10.1016/j.susc.2011.01.002⟩. ⟨hal-01811425⟩