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Creating a Ferromagnetic Ground State with Tc Above Room Temperature in a Paramagnetic Alloy through Non-Equilibrium Nanostructuring

Ye, X. 1; Fortunato, N.; Sarkar, A. 1; Geßwein, H. 2; Wang, D. ORCID iD icon 1,3; Chen, X.; Eggert, B.; Wende, H.; Brand, R. A.; Zhang, H.; Hahn, H. 1; Kruk, R. 1
1 Institut für Nanotechnologie (INT), Karlsruher Institut für Technologie (KIT)
2 Institut für Angewandte Materialien – Energiespeichersysteme (IAM-ESS), Karlsruher Institut für Technologie (KIT)
3 Karlsruhe Nano Micro Facility (KNMF), Karlsruher Institut für Technologie (KIT)

Abstract:

Materials with strong magnetostructural coupling have complex energy landscapes featuring multiple local ground states, thus making it possible to switch among distinct magnetic-electronic properties. However, these energy minima are rarely accessible by a mere application of an external stimuli to the system in equilibrium state. A ferromagnetic ground state, with Tc above room temperature, can be created in an initially paramagnetic alloy by nonequilibrium nanostructuring. By a dealloying process, bulk chemically disordered FeRh alloys are transformed into a nanoporous structure with the topology of a few nanometer-sized ligaments and nodes. Magnetometry and Mössbauer spectroscopy reveal the coexistence of two magnetic ground states, a conventional low-temperature spin-glass and a hitherto-unknown robust ferromagnetic phase. The emergence of the ferromagnetic phase is validated by density functional theory calculations showing that local tetragonal distortion induced by surface stress favors ferromagnetic ordering. The study provides a means for reaching conventionally inaccessible magnetic states, resulting in a complete on/off ferromagnetic–paramagnetic switching over a broad temperature range.


Verlagsausgabe §
DOI: 10.5445/IR/1000143292
Veröffentlicht am 03.03.2022
Originalveröffentlichung
DOI: 10.1002/adma.202108793
Scopus
Zitationen: 3
Web of Science
Zitationen: 3
Dimensions
Zitationen: 4
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien – Energiespeichersysteme (IAM-ESS)
Institut für Nanotechnologie (INT)
Karlsruhe Nano Micro Facility (KNMF)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2022
Sprache Englisch
Identifikator ISSN: 0935-9648, 1521-4095
KITopen-ID: 1000143292
HGF-Programm 43.31.01 (POF IV, LK 01) Multifunctionality Molecular Design & Material Architecture
Weitere HGF-Programme 43.35.03 (POF IV, LK 01) Structural and Functional Behavior of Solid State Systems
Erschienen in Advanced Materials
Verlag John Wiley and Sons
Band 34
Heft 11
Seiten Art.-Nr.: 2108793
Vorab online veröffentlicht am 01.12.2021
Nachgewiesen in Web of Science
Dimensions
Scopus
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