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Production of Fe nanoparticles from γ-Fe2O3 by high-pressure hydrogen reduction

Dirba, Imants ; Schwöbel, C. A. ; Zintler, Alexander ; Komissinskiy, Philipp ; Molina-Luna, Leopoldo ; Gutfleisch, Oliver (2020)
Production of Fe nanoparticles from γ-Fe2O3 by high-pressure hydrogen reduction.
In: Nanoscale Advances, 2 (10)
doi: 10.1039/D0NA00635A
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

In this work, the reduction of iron oxide γ-Fe2O3 nanoparticles by hydrogen at high pressures is studied. Increasing the hydrogen pressure enables reduction of γ-Fe2O3 to α-Fe at significantly lower temperatures. At low pressures, a temperature of 390 °C is necessary whereas at 530 bar complete reduction can be realized at temperatures as low as 210 °C. This leads to significant improvement in the final particle morphology, maintaining high surface-to-volume ratio of the nanoparticles with an average size of 47 ± 5 nm which is close to that of the precursor γ-Fe2O3. Neck formation, coalescence and growth during reduction can be significantly suppressed. Investigations of magnetic properties show that saturation magnetization of the reduced α-Fe nanoparticles decreases with particle size from 209 A m2 kg−1 at 390 °C reduction temperature to 204 A m2 kg−1 at 210 °C. Coercivity for the fine iron particles reaches 0.076 T which exceeds the theoretical anisotropy field. This is attributed to nano-scale surface effects.

Typ des Eintrags: Artikel
Erschienen: 2020
Autor(en): Dirba, Imants ; Schwöbel, C. A. ; Zintler, Alexander ; Komissinskiy, Philipp ; Molina-Luna, Leopoldo ; Gutfleisch, Oliver
Art des Eintrags: Bibliographie
Titel: Production of Fe nanoparticles from γ-Fe2O3 by high-pressure hydrogen reduction
Sprache: Englisch
Publikationsjahr: 26 August 2020
Verlag: Royal Society of Chemistry
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Nanoscale Advances
Jahrgang/Volume einer Zeitschrift: 2
(Heft-)Nummer: 10
DOI: 10.1039/D0NA00635A
Kurzbeschreibung (Abstract):

In this work, the reduction of iron oxide γ-Fe2O3 nanoparticles by hydrogen at high pressures is studied. Increasing the hydrogen pressure enables reduction of γ-Fe2O3 to α-Fe at significantly lower temperatures. At low pressures, a temperature of 390 °C is necessary whereas at 530 bar complete reduction can be realized at temperatures as low as 210 °C. This leads to significant improvement in the final particle morphology, maintaining high surface-to-volume ratio of the nanoparticles with an average size of 47 ± 5 nm which is close to that of the precursor γ-Fe2O3. Neck formation, coalescence and growth during reduction can be significantly suppressed. Investigations of magnetic properties show that saturation magnetization of the reduced α-Fe nanoparticles decreases with particle size from 209 A m2 kg−1 at 390 °C reduction temperature to 204 A m2 kg−1 at 210 °C. Coercivity for the fine iron particles reaches 0.076 T which exceeds the theoretical anisotropy field. This is attributed to nano-scale surface effects.

Fachbereich(e)/-gebiet(e): 11 Fachbereich Material- und Geowissenschaften
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Elektronenmikroskopie
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Dünne Schichten
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Funktionale Materialien
Hinterlegungsdatum: 09 Sep 2020 05:52
Letzte Änderung: 20 Nov 2020 09:00
PPN:
Projekte: This work was supported by the German Federal Ministry of Education and Research (BMBF) within the project 03X3582., This work was also supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project ID No. 405553726, TRR 270.
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