Reaction of hydrogen with the Laves phase (C14) TiCr1.78−xMnx compounds

✍ Scribed by F. Agresti; S. Lo Russo; A. Maddalena; G. Principi; G. Mazzolai; B. Coluzzi; A. Biscarini; F.M. Mazzolai; A. Tuissi

• Book ID: 103842964
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 498 KB
• Volume: 521-522
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2008.09.154

✦ Synopsis

The lattice constants a and c of the as cast hexagonal (C14) Laves phase TiCr 1.78-x Mn x (x = 0, 0.4, 0.6 and 0.8) have been measured by X-ray diffraction at room temperature as a function of the Mn content. It has been found that a decreases with increasing x while c remains almost unchanged. Being this alloy interesting as material for solid state hydrogen storage, pressure-composition isotherms have been traced on desorption mode for the H 2 gas pressure and temperature varying from 10 to 0.01 MPa and from 209 to 307 K, respectively. From the temperature dependence of the plateau pressure the molar quantities HH 2 and SH 2 associated with the hydride decomposition have been determined as a function of the Mn content. With increasing x, both HH 2 and SH 2 progressively decrease, and the desorption pressure initially decreases (for x ≤ 0.4) then slightly increases. At the same time, the pseudo-plateaus become flatter.