Ab initio investigation of FeTi–H system

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• 作者：A. Kinaci ; M.K. Aydinol
• 关键词：Intermetallic hydrides ; Hydrogen storage ; First principles simulation
• 刊名：International Journal of Hydrogen Energy
• 出版年：2007
• 出版时间：September 2007
• 年：2007
• 卷：32
• 期：13
• 页码：2466-2474
• 全文大小：982 K

文摘

In this study, a first principles search for a possible hydride with high hydrogen storage capacity was carried out in the FeTi intermetallic system. In this regard, formation energies of FeTiH_x 13735c777ca488d33f01cad690247a1a"" title=""Click to view the MathML source"">(x=1–6) hydrides are systematically investigated on the basis of crystal and electronic structures and structural stability. Total energies were calculated by ab initio pseudopotential method within the generalized gradient approximation (GGA) to density functional theory (DFT). In the stability analysis, mostly the subgroups of the space group of the FeTi structure , as well as some special cases in which Fe–Ti coordination is similar to were considered. Our calculations predicted the experimental structures of FeTiH and FeTiH₂. It was found that, the insertion of hydrogen into the structure causes an increased electron density in the electronic orbitals of Fe which were oriented towards hydrogen atoms. We have also identified a new hydride which is less stable than the experimentally observed ones, having four hydrogen atoms per chemical formula.