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Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction
In this work, the reduction of iron oxide γ-Fe(2)O(3) nanoparticles by hydrogen at high pressures is studied. Increasing the hydrogen pressure enables reduction of γ-Fe(2)O(3) to α-Fe at significantly lower temperatures. At low pressures, a temperature of 390 °C is necessary whereas at 530 bar compl...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
RSC
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9417644/ https://www.ncbi.nlm.nih.gov/pubmed/36132934 http://dx.doi.org/10.1039/d0na00635a |
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author | Dirba, I. Schwöbel, C. A. Zintler, A. Komissinskiy, P. Molina-Luna, L. Gutfleisch, O. |
author_facet | Dirba, I. Schwöbel, C. A. Zintler, A. Komissinskiy, P. Molina-Luna, L. Gutfleisch, O. |
author_sort | Dirba, I. |
collection | PubMed |
description | In this work, the reduction of iron oxide γ-Fe(2)O(3) nanoparticles by hydrogen at high pressures is studied. Increasing the hydrogen pressure enables reduction of γ-Fe(2)O(3) 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-Fe(2)O(3). 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 m(2) kg(−1) at 390 °C reduction temperature to 204 A m(2) 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. |
format | Online Article Text |
id | pubmed-9417644 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | RSC |
record_format | MEDLINE/PubMed |
spelling | pubmed-94176442022-09-20 Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction Dirba, I. Schwöbel, C. A. Zintler, A. Komissinskiy, P. Molina-Luna, L. Gutfleisch, O. Nanoscale Adv Chemistry In this work, the reduction of iron oxide γ-Fe(2)O(3) nanoparticles by hydrogen at high pressures is studied. Increasing the hydrogen pressure enables reduction of γ-Fe(2)O(3) 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-Fe(2)O(3). 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 m(2) kg(−1) at 390 °C reduction temperature to 204 A m(2) 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. RSC 2020-08-26 /pmc/articles/PMC9417644/ /pubmed/36132934 http://dx.doi.org/10.1039/d0na00635a Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/ |
spellingShingle | Chemistry Dirba, I. Schwöbel, C. A. Zintler, A. Komissinskiy, P. Molina-Luna, L. Gutfleisch, O. Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction |
title | Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction |
title_full | Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction |
title_fullStr | Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction |
title_full_unstemmed | Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction |
title_short | Production of Fe nanoparticles from γ-Fe(2)O(3) by high-pressure hydrogen reduction |
title_sort | production of fe nanoparticles from γ-fe(2)o(3) by high-pressure hydrogen reduction |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9417644/ https://www.ncbi.nlm.nih.gov/pubmed/36132934 http://dx.doi.org/10.1039/d0na00635a |
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