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arXiv · 2107.07909

Discovery and implications of hidden atomic-scale structure in a metallic meteorite

András Kovács·Laura H. Lewis·Dhanalaksmi Palanisamy·Thibaud Denneulin·Alexander Schwedt·Edward R. D. Scott·Baptiste Gault·Dierk Raabe·Rafal E. Dunin-Borkowski·Michalis Charilaou
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Abstract

Iron and its alloys have made modern civilisation possible, with metallic meteorites providing one of the human's earliest sources of usable iron as well as providing a window into our solar system's billion-year history. Here highest-resolution tools reveal the existence of a previously hidden FeNi nanophase within the extremely slowly cooled metallic meteorite NWA 6259. This new nanophase exists alongside Ni-poor and Ni-rich nanoprecipitates within a matrix of tetrataenite, the uniaxial, chemically ordered form of FeNi. The ferromagnetic nature of the nanoprecipitates combined with the antiferromagnetic character of the FeNi nanophases give rise to a complex magnetic state that evolves dramatically with temperature. These observations extend and possibly alter our understanding of celestial metallurgy, provide new knowledge concerning the archetypal Fe-Ni phase diagram and supply new information for the development of new types of sustainable, technologically critical high-energy magnets.

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András Kovács, Laura H. Lewis, Dhanalaksmi Palanisamy, Thibaud Denneulin, Alexander Schwedt, Edward R. D. Scott, Baptiste Gault, Dierk Raabe, Rafal E. Dunin-Borkowski, Michalis Charilaou. 2021-07-16. Discovery and implications of hidden atomic-scale structure in a metallic meteorite. https://doi.org/10.1021/acs.nanolett.1c02573

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