Nanostructured ternary compounds prepared by focused particle-beam induced deposition
Synthesis and Properties of Functional Materials
Final Report Abstract
The aim of this project is to fabricate nanostructured ternary compounds by means of focused electron beam induced deposition (FEBID) and to investigate their composition, microstructure, electrical- and magneto-transport properties. Owing to their potentially wide field of applications, the proposal focuses on the investigation of Heusler nanostructured compounds. In particular, the fabrication of the full-Heusler compound Co2 FeSi is the main target of the first funding period. According to the project proposal, in order to fabricate this compound three precursor gases, i.e., Co2 (CO)8, Fe(CO)5 and Si5 H12 , were to be used simultaneously. However, two main problems were encountered during fabrication: (1) The oxidation of F e atoms, which leads to the formation of magnetite, hindering the formation of Co-Fe-Si compounds. (2) The competition for adsorption sites between Fe(CO)5 and Si5 H12 molecules on the surface of the substrate during the deposition process. The attempt to solve these problems led to the two main results of this project: 1) The direct writing of CoFe alloys by means of a single-source heteronuclear precursor gas. 2) The successful fabrication of binary and ternary compounds (FeSi, Fe3Si, Co2FeSi and Fe1−xCoxSi) obtained from multilayer systems by means of electron beam mixing. These results open the route for the direct fabrication of binary and ternary nanostructured compounds either by using single-source heteronuclear precursor gases with the same stoichiometry as the target compound or by electron beam mixing of multilayer samples.
Publications
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Direct writing of CoFe alloy nanostructures by focused electron beam induced deposition from a heteronuclear precursor. Nanotechnology 26, 475701 (2015)
F. Porrati, M. Pohlit, J. Müller, S. Barth, F. Biegger, C. Gspan, H. Plank, M. Huth
