Complex Mg-based hydrides obtained by mechanosynthesis: characterization and formation kinetics

LORENA BAUM; MARCOS MEYER; LUIS MENDOZA ZELIS

Buenos Aires

Simposio; International Symposium on Metastable, Mechanically Alloyed and Nanocrystalline Materials; 2008

Ternary Mg2THy, as well as quaternary Mg2T0:5T00:5Hy, Mg-based hydrides with T; T = Fe; Co; Ni were synthesized by reactive mechanical alloying in hydrogen atmosphere at 0.3MPa. The reaction progress was followed from the H2 absorption during milling until a steady state was reached, and different kinetic behaviors were found in each case. These regimes could be related to the presence or absence of hydrogen-free Mg2T intermetallicprecursors in the respective phase diagrams. The steady state samples were characterized by X-ray diffraction and differential scanning calorimetry, and those systems including Fe were studied, in addition, with Mo¨ ssbauer spectroscopy