Eggert, Bruno G. F. ; Delczeg-Czirjak, Erna K. ; Maccari, Fernando ; Kumar, Susmit ; Gutfleisch, Oliver ; Fjellvåg, Helmer ; Hauback, Bjørn C. ; Frommen, Christoph (2022)
Exploring V-Fe-Co-Ni-Al and V-Fe-Co-Ni-Cu high entropy alloys for magnetocaloric applications.
In: Journal of Alloys and Compounds, 921
doi: 10.1016/j.jallcom.2022.166040
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
A series of V1−x-Fe-Co-Ni-Al1+x and V1−x-Fe-Co-Ni-Cu1+x high entropy alloys with varying compositions (0 ≤ x ≤ 0.75) has been investigated for magnetocaloric applications. Compositions were selected according to established properties, such as configurational entropy, atomic size difference, and enthalpy of mixing. To study the influence of composition on magnetic ordering temperatures, the V and (Al/Cu) contents were changed while the content of Fe, Co and Ni was retained at 20 at. % each. The crystal structure and microstructure of the as-cast alloys were compared to literature phase guidelines and thermodynamic calculations based on the CALPHAD approach. The V-Fe-Co-Ni-Al compounds are monophasic and crystallize in a disordered body centered cubic structure or its ordered B2 variant, while the V-Fe-Co-Ni-Cu compounds are all multiphasic. Magnetic transitions in the V-Fe-Co-Ni-Al system span over 400 K, with Curie temperature ranging from 155 K in equiatomic VFeCoNiAl, to 456 K in non-equiatomic V0.25FeCoNiAl1.75. The V-Fe-Co-Ni-Cu alloys display magnetic transitions that span about 150 K, with Curie temperature ranging from 230 K for equiatomic VFeCoNiCu to 736 K for non-equiatomic V0.25FeCoNiCu1.75. The magnetic properties of the V-Fe-Co-Ni-Cu compounds were evaluated by means of density functional theory. Individual element-specific moments, magnetic exchange integrals between atomic pairs, and Curie temperatures were calculated. V0.85FeCoNiCu1.15 is selected due to its Curie temperature of 329 K, and its calculated isothermal entropy change of 0.75 J/kg.K for a field change of 5 T is comparable to other 3d metal-based high entropy alloys that form disordered solid solutions.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2022 |
| Autor(en): | Eggert, Bruno G. F. ; Delczeg-Czirjak, Erna K. ; Maccari, Fernando ; Kumar, Susmit ; Gutfleisch, Oliver ; Fjellvåg, Helmer ; Hauback, Bjørn C. ; Frommen, Christoph |
| Art des Eintrags: | Bibliographie |
| Titel: | Exploring V-Fe-Co-Ni-Al and V-Fe-Co-Ni-Cu high entropy alloys for magnetocaloric applications |
| Sprache: | Englisch |
| Publikationsjahr: | 29 Juni 2022 |
| Verlag: | Elsevier Science Publishing |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Alloys and Compounds |
| Jahrgang/Volume einer Zeitschrift: | 921 |
| DOI: | 10.1016/j.jallcom.2022.166040 |
| Kurzbeschreibung (Abstract): | A series of V1−x-Fe-Co-Ni-Al1+x and V1−x-Fe-Co-Ni-Cu1+x high entropy alloys with varying compositions (0 ≤ x ≤ 0.75) has been investigated for magnetocaloric applications. Compositions were selected according to established properties, such as configurational entropy, atomic size difference, and enthalpy of mixing. To study the influence of composition on magnetic ordering temperatures, the V and (Al/Cu) contents were changed while the content of Fe, Co and Ni was retained at 20 at. % each. The crystal structure and microstructure of the as-cast alloys were compared to literature phase guidelines and thermodynamic calculations based on the CALPHAD approach. The V-Fe-Co-Ni-Al compounds are monophasic and crystallize in a disordered body centered cubic structure or its ordered B2 variant, while the V-Fe-Co-Ni-Cu compounds are all multiphasic. Magnetic transitions in the V-Fe-Co-Ni-Al system span over 400 K, with Curie temperature ranging from 155 K in equiatomic VFeCoNiAl, to 456 K in non-equiatomic V0.25FeCoNiAl1.75. The V-Fe-Co-Ni-Cu alloys display magnetic transitions that span about 150 K, with Curie temperature ranging from 230 K for equiatomic VFeCoNiCu to 736 K for non-equiatomic V0.25FeCoNiCu1.75. The magnetic properties of the V-Fe-Co-Ni-Cu compounds were evaluated by means of density functional theory. Individual element-specific moments, magnetic exchange integrals between atomic pairs, and Curie temperatures were calculated. V0.85FeCoNiCu1.15 is selected due to its Curie temperature of 329 K, and its calculated isothermal entropy change of 0.75 J/kg.K for a field change of 5 T is comparable to other 3d metal-based high entropy alloys that form disordered solid solutions. |
| Freie Schlagworte: | Magnetocaloric, Transition metal alloys and compounds, X-ray diffraction, Scanning electron microscopy, Computer simulations, Magnetism |
| Zusätzliche Informationen: | Papre No. 166040 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Funktionale Materialien |
| Hinterlegungsdatum: | 10 Aug 2022 07:36 |
| Letzte Änderung: | 06 Okt 2022 08:22 |
| PPN: | 498053156 |
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