(DOI: 10.2138/AM.2009.3029) The iron oxides hematite, magnetite, and goethite were studied with density functional theory to establish a consistent set of structures for both the bulk …
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The iron oxides hematite, magnetite, and goethite were studied with density functional theory to establish a consistent set of structures for both the bulk mineral and key surfaces, characterize …
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Hematite has the chemical formula of Fe 2 O 3 and is one of the most common minerals in iron ore deposits. The spin configuration of hematite is antiferromagnetic below the …
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Three natural specimens of hematite are characterized using X-ray diffraction, magnetometry, IR/Raman and Möss spectroscopy, with focus on the Morin transition. All …
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The iron atom has a strong magnetic moment due to four unpaired electrons in its 3d orbitals. When crystals are formed from iron atoms, different magnetic states can arise as …
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Hematite and magnetite are both iron ores and hold significant interest for those who study and collect minerals. These two ores have many aspects in common, as well as some notable differences that can affect their …
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The replacement of magnetite by hematite is commonly observed in various geologic systems. In contrast to the formation of hematite by a solid-state oxidation, numerous …
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Therefore, this lack of transformation into magnetite in the presence of strongly bonded ligand point out the key role of Fe II surface sorbed and electron injection within the …
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We present FORC diagrams for predominantly single-domain (SD) synthetic aluminous hematite (α -Fe 2-x Al x O 3) and goethite (α - …
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Bulk hematite and magnetite structures were modeled using experimental lattice constants and positions as available from the structural database in Materials Studio 6.1. ...
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Three key interfaces deserve attention: hematite–substrate (usually FTO), hematite–catalysts, and hematite grain boundaries. ... The migration of holes from the bulk to the surface of …
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It must be pointed out that maghemite (γ-Fe 2 O 3) with a cubic spinel structure is a crucial material for various applications, including spin electronic devices, high-density …
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Hardness and elastic properties of pure (crystal) and complex (product of corrosion) iron oxides, magnetite (Fe 3 O 4), hematite (α-Fe 2 O 3) and goethite (α-FeO·OH), were …
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Magnetite has an inverse spinel structure with Fe (III) ions distributed randomly between octahedral and tetrahedral sites, and Fe (II) ions in octahedral sites [4]. Maghemite has a spinel...
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Both the surface structure and the presence of adsorbed water strongly differentiate electron hopping rates between bulk and surface environments by orders of magnitude. It is …
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From Fig. 6 (b) and (c), it can be observed that nano-magnetite and nano-maghemite keep their cubic structures at temperatures below 400 °C, indicating that the phase …
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Hematite (α-Fe 2 O 3) surfaces represent one of the most common redox-active interfaces in the environment, playing an important role in the biogeochemical cycling of metal …
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The maghemite crystal structure has been the subject of controversy in the last years. A work by Greaves [40] using powder neutron diffraction proposed a tetragonal P4 3 2 1 …
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The three main iron oxides found in nature are magnetite (Fe₃O₄), maghemite (γ-Fe₂O₃), and hematite (α-Fe₂O₃). Magnetite is the oldest and most magnetic, while maghemite …
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organic-magnetite interfaces, we have chosen to focus on the theoretical description of the electronic and magnetic prop-erties of magnetite itself. Magnetite has a cubic …
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[1] First-order reversal curve (FORC) diagrams have become a standard tool in rock magnetism, yet magnetite is the only magnetic mineral that is well characterized using FORC diagrams. We present FORC diagrams for …
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The iron oxides hematite, magnetite, and goethite were studied with density functional theory to establish a consistent set of structures for both the bulk mineral and key …
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Surface roughness and porosity, at macroscopic and molecular scales, constitute key properties that influence most sorption phenomena. In first approximation, the direct …
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33 Magnetite: Properties, Synthesis, & Application Lee Blaney SYNOPSIS The subsequent report presents scientific data concerning properties of micro- (diameter in 10-6 m meter range) and …
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Hematite carries magnetic signals of interest in tectonic, paleoclimatic, paleomagnetic, and planetary studies. First-order reversal curve (FORC) diagrams have become an important tool for assessing the domain …
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computational studies of the bulk crystal and electronic structures of hematite, magnetite, and goethite. Having established their validity by comparison with published experimental data, we …
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4.1.2.2 Magnetite. Magnetite (Fe 3 O 4) is a rock mineral that contains ferrous (FeO) and ferric (Fe 2 O 3) iron species.As reported in [89], the resistivity ρ of Fe 3 O 4 is around 4.0 × 10 −3 Ω·m, …
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Magnetite (Fe 3 O 4) is ferromagnetic, leading to many investigations of its magnetic properties and uses [5].Other applications include its usage as a catalyst for …
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1. Introduction. Hematite (α-Fe 2 O 3) is the major iron rock-forming mineral and, along with magnetite (Fe 3 O 4), it is one of two archetypical naturally-occurring magnetic …
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Also the Boettger relation does not converge very well for this surface, because the bulk energy is calculated from two slabs of similar ... [17] Martin G J, Cutting R S, Vaughan D J …
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