Investigations on the synthesis, structural and microstructural characterizations of Mg-based K2PtCl6 type (Mg2FeH6) hydrogen storage material prepared by mechanical alloying
| العنوان: | Investigations on the synthesis, structural and microstructural characterizations of Mg-based K2PtCl6 type (Mg2FeH6) hydrogen storage material prepared by mechanical alloying |
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| المؤلفون: | Jean-Louis Bobet, D.J. Davidson, O.N. Srivastava, S. S. Sai Raman |
| المساهمون: | Department of Physics [Varanasi], Banaras Hindu University [Varanasi] (BHU), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB) |
| المصدر: | Journal of Alloys and Compounds Journal of Alloys and Compounds, Elsevier, 2002, 333 (1-2), pp.282-290. ⟨10.1016/S0925-8388(01)01729-7⟩ |
| بيانات النشر: | Elsevier, 2002. |
| سنة النشر: | 2002 |
| مصطلحات موضوعية: | Materials science, Rietveld refinement, Hydride, Mechanical Engineering, Metals and Alloys, Analytical chemistry, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Crystallography, Lattice constant, Hydrogen absorbing materials, Mechanics of Materials, Phase (matter), Powder metallurgy, Materials Chemistry, Mechanical alloying, Transition metal alloys, 0210 nano-technology, Ball mill, Powder diffraction, Diffractometer |
| الوصف: | This paper deals with the formation of new ternary hydride Mg 2 FeH 6 (K 2 PtCl 6 type) in a single-step procedure following the process of mechanical alloying of initial stoichiometric ingredients Mg and Fe under hydrogen. The optimum yield of formation of single phase Mg 2 FeH 6 was achieved by hydrogen (∼10 atm.) milling of constituent elements at a speed of 400 rpm for various milling durations. The structural characterization of the ball-milled (2 Mg+Fe) powder was carried out using Philips X-ray diffractometer by taking samples from the attritor mill at regular intervals of time. It was found that the Mg 2 FeH 6 phase starts forming at a milling duration of 14 h and the optimum Mg 2 FeH 6 phase formation was obtained at 20 h. The proportion of this phase was estimated by employing Rietveld refinement analysis of the X-ray powder diffraction data and it was found to be 63%. This is the highest phase proportion reported so far for the Mg 2 FeH 6 phase when formed from elemental Mg and Fe following the route of mechanical alloying. Together with the Mg 2 FeH 6 phase, some quantity of Fe (about 37%) is also present. Fe, being a magnetic impurity, can be removed leaving the Mg 2 FeH 6 content to be nearly 90–100%. However, such purification was not done in the present investigation. We also investigated synthesis of the material obtained by longer milling durations of 25, 28 and 30 h. The XRD patterns for the 25, 28 and 30 h ball-milled materials revealed that the intensity of Mg 2 FeH 6 peaks is reduced in comparison to the Fe peaks. This implies that beyond 20 h, there is no further increase in the phase proportion and the amorphization starts taking place. The post-sintering process of these mechanically alloyed samples did not improve the Mg 2 FeH 6 phase proportion and yield as evidenced by XRD. The X-ray structural characterizations revealed that the as-milled Mg 2 FeH 6 material (milling duration of 20 h; under H 2 pressure ∼10 atm., speed ∼400 rpm) corresponds to the known face centered cubic structure with lattice parameter a =0.6446(2) nm. The elemental (chemical) compositional analysis was carried out for the mechanically alloyed Mg 2 FeH 6 materials using the EDAX technique. The results confirm the correct stoichiometric ratio of the initial mixture (2Mg+Fe). The surface morphologies of the (2Mg+Fe) mixture before and after mechanical alloying are performed using scanning electron microscopic technique. The SEM explorations reveal the spongy like feature of Mg 2 FeH 6 agglomerates. |
| اللغة: | English |
| تدمد: | 0925-8388 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6b71fbe0b4ef8c1056898bfaf584ff2bTest http://hdl.handle.net/20.500.12278/17600Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....6b71fbe0b4ef8c1056898bfaf584ff2b |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 09258388 |
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