Atomistic simulation and ab initio study of the defect structure of spinel-related Li0.5−0.5xMgxFe2.5−0.5xO4

Widatallah, H. M.; Moore, Elaine; Babo, A.A.; Al-Barwani, Muataz; Elzain, M. E.

doi:10.1016/j.materresbull.2012.08.048

Cited by 8 publications

(5 citation statements)

References 28 publications

(68 reference statements)

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“…The spin-down states, near the Fermi level (⁓ -0.5-0.0 eV), are mainly a contribution of the 3d-Fe 2+ (B1/B4) ions that are ascribed to the localized t2g minority charge indicating an orbital ordering in which the t2g spin-down states of Fe 2+ ions are occupied while those of Fe 3+ are not [51,52]. In general, the agreement of the above results for Fe3O4 with previous DFT calculations [13,19,20,39] supports the adequacy of using the GGA+U approach for the Mn 2+ -doped Fe3O4 electronic structure calculations. Additionally, we summarize in Table 4 the calculated hyperfine parameters and magnetic moments at certain Fe sites in the 1×1×2 Fe3O4…”

Section: The Electronic Hyperfine and Magnetic Properties Of Fe3o4supporting

confidence: 86%

“…Of these methods, atomistic simulations have been successfully used to optimize the structures of iron oxides, including the distribution of point defects in cation-doped systems by minimizing the lattice energy [32][33][34][35][36]. It has also been shown that conflicting defect structure models for cation-doped iron oxides inferred from experimental data could be unambiguously resolved by combining atomistic simulation and ab initio DFT calculations [36,39]. To our knowledge, there is only one published atomistic simulation study on the defect structure of Sn 4+ /Ti 4+ doped Fe3O4 [40].…”

Section: Introductionmentioning

confidence: 99%

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Computational modeling of the defect structure, hyperfine and magnetic properties of the Mn2+-doped magnetite of the composition Mn Fe3-O4 (y = ⅔ x)

Al-Rashdi

Elzain

Al-Barwani

et al. 2023

Materials Research Bulletin

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Section: The Electronic Hyperfine and Magnetic Properties Of Fe3o4supporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Computational modeling of the defect structure, hyperfine and magnetic properties of the Mn2+-doped magnetite of the composition Mn Fe3-O4 (y = ⅔ x)

Al-Rashdi

Elzain

Al-Barwani

et al. 2023

Materials Research Bulletin

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“…The position of magnesium ions in Mg 2þ -doped lithium ferrite of the composition Li 0.5−0.5x Mg x Fe 2.5−0.5x O 4 has been investigated by interatomic potential and DFT calculations. 119 The lowest energy structure was found for Mg 2þ ions evenly replacing Li þ and Fe 3þ ions on octahedral sites. This occupation affects a decrease in magnetization for the Mg 2þ -doped ferrite relative to the undoped lithium ferrite.…”

Section: Magnetic Propertiesmentioning

confidence: 96%

Photoelectrochemical and theoretical investigations of spinel type ferrites (M_xFe_3−xO₄) for water splitting: a mini-review

et al. 2016

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Solar-assisted water splitting using photoelectrochemical cells (PECs) is one of the promising pathways for the production of hydrogen for renewable energy storage. The nature of the semiconductor material is the primary factor that controls the overall energy conversion efficiency. Finding semiconductor materials with appropriate semiconducting properties (stability, efficient charge separation and transport, abundant, visible light absorption) is still a challenge for developing materials for solar water splitting. Owing to the suitable bandgap for visible light harvesting and the abundance of iron-based oxide semiconductors, they are promising candidates for PECs and have received much research attention. Spinel ferrites are subclasses of iron oxides derived from the classical magnetite (Fe II Fe III 2 O 4) in which the Fe II is replaced by one (some cases two) additional divalent metals. They are generally denoted as M x Fe 3−x O 4 (M ¼ Ca, Mg, Zn, Co, Ni, Mn, and so on) and mostly crystallize in spinel or inverse spinel structures. In this mini review, we present the current state of research in spinel ferrites as photoelectrode materials for PECs application. Strategies to improve energy conversion efficiency (nanostructuring, surface modification, and heterostructuring) will be presented. Furthermore, theoretical findings related to the electronic structure, bandgap, and magnetic properties will be presented and compared with experimental results. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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“…The variation of room-temperature dc-resistivity as a function of composition is presented in Table 1. It shows a regular increase with Zn content as shown in Figure 6 and can be explained on the basis of Verwey mechanism of electron hopping between two valance states distributed randomly on equivalent lattice sites [18][19][20][21][22][23]. The temperature dependence of dc-resistivity was also studied in the temperature range 308-398 K as displayed in the Figure 7 that shows an almost linear decrease in resistivity with temperature suggesting semiconductor behavior of the ferrite materials.…”

Section: +mentioning

confidence: 97%

Effect of Zn dopant on Properties of Li ferrite Synthesized by Solution Combustion Method

Anu¹

2017

International Advanced Research Journal in Science, Engineering

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Herein, Urea assisted solution combustion method has been used for the preparation of stoichiometrically pure and Zn doped Li ferrites. Urea acts as a capping agent and helps in the formation of nanostructures. Solution combustion method helps easier formation of ferrites in a single step, at relatively lower temperature and in shorter time than the reported methods. Powder X-ray diffraction (XRD) studies with diffractometer indicate high purity, single phase spinel ferrites formation. Magnetic studies by vibratory sample magnetometer (VSM) reveal an increase in the magnitude of saturation magnetization with increasing Zn content up to x = 0.3. The Zn doped Li ferrite formed possess high dc-resistivity values which make them suitable for high-frequency applications. Apart from the academic interest involved, these investigations are of technological importance in the view of the fact that their end products (ferrites) play a key role as electro-magnetic materials in the modern industry.Keywords: Solution combustion method, powder X-ray diffraction, Powder X-ray diffraction, saturation magnetization, dc-resistivity. I INTRODUCTIONAlkali metal ferrites find extensive use in microwave components due to their attractive electrical and magnetic properties [1][2][3][4][5][6][7][8][9][10][11]. Ferrites have been reported as better electromagnetic materials than pure metals because of their low cost, high resistivity and ease of preparation. The properties of the ferrite materials, which decide the application areas, are generally governed by the chemical compositions along with the procedures followed for their preparation. Therefore, the molecular engineering of ferrite composition and employment of appropriate process parameters play a significant role in tailoring the material properties for a specific need. The properties of the ferrites can be modified by substituting the optimum amount of metal ions as dopant in the basic compositional formulae. It is, therefore, desirable to investigate and understand the dependence of composition on magnetic/electric behavior of these ferrites. Ferrite nanoparticles show unusual magnetic properties such as single domain behavior and superparamagnetism which are not observed in bulk material [12,13]. Also, the resistivity of the ferrites at room temperature can vary from 10 -2 to 10 11 ohm-cm [14][15][16]. The change in the resistivity is brought about by substitution of some appropriate metal ion in the metal site. To obtained sample with high resistivity, it is necessary to ensure that there are no ferrous ions in the stoichiometric ferrite. Therefore, chemical aspect has become the most important factor in the design and preparation of ferrite materials. Solution combustion method has been found to be the most suitable technique for the synthesis of a particular mixed ferrite composition. The properties of the final product (particle size, surface area and porosity) depend on the way the combustion is conducted. The departure of gases favours the desegregation of th...

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Atomistic simulation and ab initio study of the defect structure of spinel-related Li0.5−0.5xMgxFe2.5−0.5xO4

Cited by 8 publications

References 28 publications

Computational modeling of the defect structure, hyperfine and magnetic properties of the Mn2+-doped magnetite of the composition Mn Fe3-O4 (y = ⅔ x)

Computational modeling of the defect structure, hyperfine and magnetic properties of the Mn2+-doped magnetite of the composition Mn Fe3-O4 (y = ⅔ x)

Photoelectrochemical and theoretical investigations of spinel type ferrites (M_xFe_3−xO₄) for water splitting: a mini-review

Effect of Zn dopant on Properties of Li ferrite Synthesized by Solution Combustion Method

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Atomistic simulation and ab initio study of the defect structure of spinel-related Li0.5−0.5xMgxFe2.5−0.5xO4

Cited by 8 publications

References 28 publications

Computational modeling of the defect structure, hyperfine and magnetic properties of the Mn2+-doped magnetite of the composition Mn Fe3-O4 (y = ⅔ x)

Computational modeling of the defect structure, hyperfine and magnetic properties of the Mn2+-doped magnetite of the composition Mn Fe3-O4 (y = ⅔ x)

Photoelectrochemical and theoretical investigations of spinel type ferrites (MxFe3−xO4) for water splitting: a mini-review

Effect of Zn dopant on Properties of Li ferrite Synthesized by Solution Combustion Method

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Photoelectrochemical and theoretical investigations of spinel type ferrites (M_xFe_3−xO₄) for water splitting: a mini-review