Amorphous Al1-xTix, Al1-xVx, and Al1-xFex phases in the hydrogen cycled TiCl3, VCl3 and FeCl3 enhanced NaAlH4 systems

作者：Pitt M P^*; Vullum P E; Sorby M H; Emerich H; Paskevicius M; Buckley C E; Gray E MacA; Walmsley J C; Holmestad R; Hauback B C

来源：Journal of Alloys and Compounds, 2012, 521: 112-120.

DOI：10.1016/j.jallcom.2012.01.062

• Metal hydrides
• Amorphous materials
• Transition metal alloys and compounds
• Synchrotron radiation
• Transmission electron microscopy (TEM)

The twice hydrogen (H) cycled planetary milled (PM) and cryo milled (CM) NaAlH4 + xTMCl(3) (transition metal (TM) = Ti, V, Fe) systems (x %26gt; 0.1) have been studied by high resolution synchrotron X-ray diffraction, and high resolution transmission electron microscopy (TEM). Intense primary amorphous (a-) Al1-xTMx halos are evident in diffraction data of PM samples for V and Fe, and in CM samples for Ti, V, and Fe. Weaker primary amorphous Al1-xTix halos are evident in PM samples for Ti. The Ti poor a-Al(1-x)Tix phase observed for NaAlH4 + xTiCl(3) (x %26gt; 0.1) ranges in composition from a-Al86.5Ti13.5 -%26gt; a-Al92Ti8. High resolution TEM studies of the Al1-xVx phases in the H cycled PM NaAlH4 + 0.1VCl(3) system demonstrates that a nanoscopic composite morphology can exist between face centred cubic (fcc) crystalline (c-) Al1-xVx and a-Al1-xVx phases, with the c-Al1-xVx/a-Al1-xVx composite embedded on the NaAlH4 surface. The amorphous Al1-xVx reaches ca. 28 at.% V.

• 出版日期2012-4-25