biostudies-literatureKovacs ADeutsche ForschungsgemeinschaftEuropean Research CouncilAdvanced Research Projects Agency - EnergyH2020 Research InfrastructuresNortheastern University8135-8142https://www.ebi.ac.uk/biostudies/studies/S-EPMC8519181biostudies-literatureUnknown21(19)Iron and its alloys have made modern civilization 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 gives rise to a complex magnetic state that evolves dramatically with temperature. These observations extend and possibly alter our understanding of celesNano lettersDiscovery and Implications of Hidden Atomic-Scale Structure in a Metallic Meteorite.PMC8519181856538823717405553726Gault BCharilaou MPalanisamy DRaabe DDenneulin TScott ERDDunin-Borkowski RESchwedt AKovacs ALewis LHfalseDiscovery and Implications of Hidden Atomic-Scale Structure in a Metallic Meteorite.Iron and its alloys have made modern civilization 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 gives rise to a complex magnetic state that evolves dramatically with temperature. These observations extend and possibly alter our understanding of celes2021-01-01T00:00:00Z2021 Oct2025-04-19T18:09:39.628Z2025-04-19T18:09:39.628ZS-EPMC85191813452991610.1021/acs.nanolett.1c02573