High-pressure synthesis of Na_{1鈭?span style='font-style: italic'>x}Li_xMgH₃ perovskite hydrides

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• 作者：R. Martí ; nez-Coronado^a ; ^{rmartinez@icmm.csic.es} ; J. S&#225 ; nchez-Bení ; tez^a ; ^b ; M. Retuerto^c ; M.T. Fern&#225 ; ndez-Dí ; az^d ; J.A. Alonso^a
• 关键词：Metal hydrides ; NaMgH3 ; Neutron powder diffraction ; High-pressure synthesis
• 刊名：Journal of Alloys and Compounds
• 出版年：2012
• 期刊代码：45_09258388
• 类别：ms
• 出版时间：5 May, 2012
• 卷：522
• 期：Complete
• 页码：101-105
• 文件大小：440 K

摘要

Magnesium base alloys are very attractive for hydrogen storage due to their large hydrogen capacity, small weight and low-cost. We have designed a new synthesis method for the ternary metal hydride perovskite system Na_1鈭?em>xLi_xMgH₃, based on the direct reaction of simple hydrides under high-pressure and moderate-temperature conditions. Well-crystallized samples were obtained in a piston-cylinder hydrostatic press at moderate pressures of 2 GPa and temperatures around 750 掳C from mixtures of MgH₂, NaH and LiH enclosed in gold capsules. X-ray and neutron powder diffraction analysis were used to identify the purity of the samples and provide an accurate description of the crystal structure features (GdFeO₃ type). Na_1鈭?em>xLi_xMgH₃ hydrides series (0 鈮?#xA0;x 鈮?#xA0;0.18) show an orthorhombic symmetry with space group Pnma (No. 62). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been carried out to determine the hydrogen desorption temperatures.