Controlling the magnetocrystalline anisotropy of ε-Fe2O3
The magnetocrystalline anisotropy of pristine and Co-substituted ε-Fe2O3 is investigated by density functional calculations. The epsilon-iron oxide is the only polymorph of Fe2O3 magnetoelectric in its antiferromagnetic ground states other crystalline forms being α-Fe2O3 (hematite), β-Fe2O3, and γ-F...
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AIP Publishing LLC
2019-03-01
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Series: | AIP Advances |
Online Access: | http://dx.doi.org/10.1063/1.5080144 |
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author | Imran Ahamed Ralph Skomski Arti Kashyap |
author_facet | Imran Ahamed Ralph Skomski Arti Kashyap |
author_sort | Imran Ahamed |
collection | DOAJ |
description | The magnetocrystalline anisotropy of pristine and Co-substituted ε-Fe2O3 is investigated by density functional calculations. The epsilon-iron oxide is the only polymorph of Fe2O3 magnetoelectric in its antiferromagnetic ground states other crystalline forms being α-Fe2O3 (hematite), β-Fe2O3, and γ-Fe2O3 (maghemite). The magnetizations of the four iron sublattices are antiferromagnetically aligned with slightly different magnetic moments resulting in a ferrimagnetic structure. Compared to the naturally occurring hematite and maghemite, bulk ε-Fe2O3 is difficult to prepare, but ε-Fe2O3 nanomaterials of different geometries and feature sizes have been fabricated. A coercivity of 20 kOe [2 T] was reported in nanocomposites of ε-Fe2O3, and an upper bound for the magnetic anisotropy constant K at a low temperature of ε-Fe2O3 is previously measured to be 0.1 MJ/m3. In the Co-substituted oxides, one octahedral or tetrahedral Fe atom per unit cell has been replaced by Co. The cobalt substitution substantially enhances magnetization and anisotropy. |
first_indexed | 2024-04-13T01:32:57Z |
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issn | 2158-3226 |
language | English |
last_indexed | 2024-04-13T01:32:57Z |
publishDate | 2019-03-01 |
publisher | AIP Publishing LLC |
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spelling | doaj.art-31738a1bc03042e482f8acd3ed4747bf2022-12-22T03:08:28ZengAIP Publishing LLCAIP Advances2158-32262019-03-0193035231035231-410.1063/1.5080144064992ADVControlling the magnetocrystalline anisotropy of ε-Fe2O3Imran Ahamed0Ralph Skomski1Arti Kashyap2School of Basic Sciences, Indian Institute of Technology, Mandi, HP 175001, IndiaNebraska Center for Materials and Nanoscience & Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USASchool of Basic Sciences, Indian Institute of Technology, Mandi, HP 175001, IndiaThe magnetocrystalline anisotropy of pristine and Co-substituted ε-Fe2O3 is investigated by density functional calculations. The epsilon-iron oxide is the only polymorph of Fe2O3 magnetoelectric in its antiferromagnetic ground states other crystalline forms being α-Fe2O3 (hematite), β-Fe2O3, and γ-Fe2O3 (maghemite). The magnetizations of the four iron sublattices are antiferromagnetically aligned with slightly different magnetic moments resulting in a ferrimagnetic structure. Compared to the naturally occurring hematite and maghemite, bulk ε-Fe2O3 is difficult to prepare, but ε-Fe2O3 nanomaterials of different geometries and feature sizes have been fabricated. A coercivity of 20 kOe [2 T] was reported in nanocomposites of ε-Fe2O3, and an upper bound for the magnetic anisotropy constant K at a low temperature of ε-Fe2O3 is previously measured to be 0.1 MJ/m3. In the Co-substituted oxides, one octahedral or tetrahedral Fe atom per unit cell has been replaced by Co. The cobalt substitution substantially enhances magnetization and anisotropy.http://dx.doi.org/10.1063/1.5080144 |
spellingShingle | Imran Ahamed Ralph Skomski Arti Kashyap Controlling the magnetocrystalline anisotropy of ε-Fe2O3 AIP Advances |
title | Controlling the magnetocrystalline anisotropy of ε-Fe2O3 |
title_full | Controlling the magnetocrystalline anisotropy of ε-Fe2O3 |
title_fullStr | Controlling the magnetocrystalline anisotropy of ε-Fe2O3 |
title_full_unstemmed | Controlling the magnetocrystalline anisotropy of ε-Fe2O3 |
title_short | Controlling the magnetocrystalline anisotropy of ε-Fe2O3 |
title_sort | controlling the magnetocrystalline anisotropy of ε fe2o3 |
url | http://dx.doi.org/10.1063/1.5080144 |
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