Structure and magnetism of self-organized Ge(1-x)Mn(x) nano-columns

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dc.creatorDevillers, Thibaut
dc.creatorJamet, Matthieu
dc.creatorBarski, André
dc.creatorPoydenot, Valier
dc.creatorBayle-Guillemaud, Pascale
dc.creatorBellet-Amalric, Edith
dc.creatorCherifi, Salia
dc.creatorCibert, Joël
dc.date2007-05-04
dc.date.accessioned2026-07-07T10:00:28Z
dc.date.available2026-07-07T10:00:28Z
dc.descriptionWe report on the structural and magnetic properties of thin Ge(1-x)Mn(x)films grown by molecular beam epitaxy (MBE) on Ge(001) substrates at temperatures (Tg) ranging from 80deg C to 200deg C, with average Mn contents between 1 % and 11 %. Their crystalline structure, morphology and composition have been investigated by transmission electron microscopy (TEM), electron energy loss spectroscopy and x-ray diffraction. In the whole range of growth temperatures and Mn concentrations, we observed the formation of manganese rich nanostructures embedded in a nearly pure germanium matrix. Growth temperature mostly determines the structural properties of Mn-rich nanostructures. For low growth temperatures (below 120deg C), we evidenced a two-dimensional spinodal decomposition resulting in the formation of vertical one-dimensional nanostructures (nanocolumns). Moreover we show in this paper the influence of growth parameters (Tg and Mn content) on this decomposition i.e. on nanocolumns size and density. For temperatures higher than 180deg C, we observed the formation of Ge3Mn5 clusters. For intermediate growth temperatures nanocolumns and nanoclusters coexist. Combining high resolution TEM and superconducting quantum interference device magnetometry, we could evidence at least four different magnetic phases in Ge(1-x)Mn(x) films: (i) paramagnetic diluted Mn atoms in the germanium matrix, (ii) superparamagnetic and ferromagnetic low-Tc nanocolumns (120 K < Tc < 170 K), (iii) high-Tc nanocolumns (Tc> 400 K) and (iv) Ge3Mn5 clusters.
dc.description10 pages 2 colonnes revTex formatted
dc.identifierhttps://arxiv.org/abs/0705.0566
dc.identifierhttp://arxiv.org/abs/0705.0566
dc.identifierPhysical Review B 76 (2007) 205306
dc.identifierdoi:10.1103/PhysRevB.76.205306
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/168331
dc.subjectMaterials Science
dc.titleStructure and magnetism of self-organized Ge(1-x)Mn(x) nano-columns
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