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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Veber, Philippe
West University of Timişoara
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (16/16 displayed)
- 2022Phase Transitions and Physical Properties of the Mixed Valence Iron Phosphate Fe3(PO3OH)4(H2O)4
- 2018Metastable ferroelectric phase and crossover in the Ba2NdFeNb4−xTaxO15 TTB solid solutioncitations
- 2018Spinodal decomposition in lead-free piezoelectric BaTiO3–CaTiO3–BaZrO3 crystalscitations
- 2018Spinodal Decomposition in Lead-free Piezoelectric BaTiO3 –CaTiO3 –BaZrO3 Crystalscitations
- 2016Orientation-dependent electromechanical properties of Mn-doped (Li,Na,K)(Nb,Ta)O3 single crystalscitations
- 2016Adjustable dielectric properties of BaTiO3 containing MgO inclusions deformable under Spark Plasma Sinteringcitations
- 2015Growth and Characterization of Lead-free Piezoelectric Single Crystalscitations
- 2014Growth and characterization of Ba2LnFeNb4O15 (Ln = Pr, Nd, Sm, Eu) relaxor single crystalscitations
- 2014Continuous cross-over from ferroelectric to relaxor state and piezoelectric properties of BaTiO3-BaZrO3-CaTiO3 single crystalscitations
- 2013Yb3+ doped Lu2O3 transparent ceramics by spark plasma sinteringcitations
- 2013Raman and fluorescence correlative microscopy in polarized light to probe local femtosecond laser-induced amorphization of the doped monoclinic crystal LYB:Eucitations
- 2013Growth and characterization of centimeter-sized Ba2LaFeNb4O15 crystals from high-temperature solution under a controlled atmospherecitations
- 2013Highlights on the Anisotropic Oxygen Transport Properties of Nickelates with K2NiF4-Type Structure: Links with the Electrochemical Properties of the Corresponding IT-SOFC's Cathodescitations
- 2012Structural analysis, growth and characterization of cadmiumgalliumtelluride (Cd0.89Ga0.11Te) thermoelectric semiconductor single crystals
- 2012Structuralanalysis, growth and characterization of cadmiumgalliumtelluride (Cd0.89Ga0.11Te) thermoelectric semiconductor single crystals
- 2012Cation ordering in the double tungstate LiFe(WO4)2citations
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article
Phase Transitions and Physical Properties of the Mixed Valence Iron Phosphate Fe3(PO3OH)4(H2O)4
Abstract
<jats:p>Iron phosphate materials have attracted a lot of attention due to their potential as cathode materials for lithium-ion rechargeable batteries. It has been shown that lithium insertion or extraction depends on the Fe mixed valence and reduction or oxidation of the Fe ions’ valences. In this paper, we report a new synthesis method for the Fe3(PO3OH)4(H2O)4 mixed valence iron phosphate. In addition, we perform temperature-dependent measurements of structural and physical properties in order to obtain an understanding of electronic–structural interplay in this compound. Scanning electron microscope images show needle-like single crystals of 50 μm to 200 μm length which are stable up to approximately 200 °C, as revealed by thermogravimetric analysis. The crystal structure of Fe3(PO3OH)4(H2O)4 single crystals has been determined in the temperature range of 90 K to 470 K. A monoclinic isostructural phase transition was found at ~213 K, with unit cell volume doubling in the low temperature phase. While the local environment of the Fe2+ ions does not change significantly across the structural phase transition, small antiphase rotations occur for the Fe3+ octahedra, implying some kind of electronic order. These results are corroborated by first principle calculations within density functional theory, which also point to ordering of the electronic degrees of freedom across the transition. The structural phase transition is confirmed by specific heat measurements. Moreover, hints of 3D antiferromagnetic ordering appear below ~11 K in the magnetic susceptibility measurements. Room temperature visible light absorption is consistent with the Fe2+/Fe3+ mixed valence.</jats:p>