Atomic scale study of thermal reduction of nano goethite coexisting with magnetite
Evolution of the local structure and magnetic properties of nano particles of goethite having magnetite as a composite due to controlled annealing treatments in vacuum has been studied using Mossbauer spectroscopy. Importance of size, defect associated with structural OH- for the observed structural...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2013-02-01
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| Series: | AIP Advances |
| Online Access: | http://link.aip.org/link/doi/10.1063/1.4790614 |
| _version_ | 1828256731779563520 |
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| author | L. Herojit singh R. Govindaraj R. Mythili G. Amarendra C. S. Sundar |
| author_facet | L. Herojit singh R. Govindaraj R. Mythili G. Amarendra C. S. Sundar |
| author_sort | L. Herojit singh |
| collection | DOAJ |
| description | Evolution of the local structure and magnetic properties of nano particles of goethite having magnetite as a composite due to controlled annealing treatments in vacuum has been studied using Mossbauer spectroscopy. Importance of size, defect associated with structural OH- for the observed structural and magnetic properties of goethite has been emphasized in this study. Present Mossbauer results show that thermal annealing at low temperatures (420-550 K) lead to a partial conversion / reduction of orthorhombic goethite to cubic spinel oxides such as maghemite and off-stochiometric magnetite. This study further establishes that annealing treatments beyond 650 K predominantly results in topotactic conversion of goethite to haematite. Underlying physics of the transitions of goethite to iron oxides and the important role of desorbed hydrogen for the orthorhombic to cubic structural transitions has been elucidated in this study. |
| first_indexed | 2024-04-13T02:32:25Z |
| format | Article |
| id | doaj.art-da6accb144cd4fe7b1d33ff4372a846f |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-04-13T02:32:25Z |
| publishDate | 2013-02-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-da6accb144cd4fe7b1d33ff4372a846f2022-12-22T03:06:31ZengAIP Publishing LLCAIP Advances2158-32262013-02-013202210102210110.1063/1.4790614Atomic scale study of thermal reduction of nano goethite coexisting with magnetiteL. Herojit singhR. GovindarajR. MythiliG. AmarendraC. S. SundarEvolution of the local structure and magnetic properties of nano particles of goethite having magnetite as a composite due to controlled annealing treatments in vacuum has been studied using Mossbauer spectroscopy. Importance of size, defect associated with structural OH- for the observed structural and magnetic properties of goethite has been emphasized in this study. Present Mossbauer results show that thermal annealing at low temperatures (420-550 K) lead to a partial conversion / reduction of orthorhombic goethite to cubic spinel oxides such as maghemite and off-stochiometric magnetite. This study further establishes that annealing treatments beyond 650 K predominantly results in topotactic conversion of goethite to haematite. Underlying physics of the transitions of goethite to iron oxides and the important role of desorbed hydrogen for the orthorhombic to cubic structural transitions has been elucidated in this study.http://link.aip.org/link/doi/10.1063/1.4790614 |
| spellingShingle | L. Herojit singh R. Govindaraj R. Mythili G. Amarendra C. S. Sundar Atomic scale study of thermal reduction of nano goethite coexisting with magnetite AIP Advances |
| title | Atomic scale study of thermal reduction of nano goethite coexisting with magnetite |
| title_full | Atomic scale study of thermal reduction of nano goethite coexisting with magnetite |
| title_fullStr | Atomic scale study of thermal reduction of nano goethite coexisting with magnetite |
| title_full_unstemmed | Atomic scale study of thermal reduction of nano goethite coexisting with magnetite |
| title_short | Atomic scale study of thermal reduction of nano goethite coexisting with magnetite |
| title_sort | atomic scale study of thermal reduction of nano goethite coexisting with magnetite |
| url | http://link.aip.org/link/doi/10.1063/1.4790614 |
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