Reactive Milling of Magnesium under Hydrogen Using Transition Metals and Their Fluorides as Additives

摘要

In the present report, we display and compare the effects of different nanocrystalline additives (MgF_2, Fe, NbH_(0.89) and FeF_3) on the formation of MgH_2 by reactive milling. The H-desorption behavior of the as-prepared nanocomposites is also evaluated. A combined catalytic effect is observed due to the synergic action of MgF_2 and Fe (or NbH_(0.89)) on the hydrogenation rate during processing. The transition metal fluorides promote as well the MgH_2 synthesis. Then using selected combination of additives (e.g. 5 mol.% FeF_3) and intense milling conditions leads to a full and fast synthesis of MgH_2.