Effect of partial substitution of nickel for copper on LaNi5 activation

Authors :: Veremeeva, O.
Yakovleva, N.
Klyamkin, S.
Berdonosova, E.
Shelekhov, E.
Source :: Russian Chemical Bulletin; June 2006, Vol. 55 Issue: 6 p949-954, 6p
Publication Year :: 2006
Abstract: Abstract: The first cycles of hydrogen absorption-desorption in LaNi<subscript>5</subscript>-H<subscript>2</subscript> and LaNi<subscript>4.5</subscript>Cu<subscript>0.5</subscript>-H<subscript>2</subscript> systems were studied using Tian-Calvet differential heat-conduction microcalorimetry, volumetric measurements, and powder X-ray diffraction. The diffraction profiles were analyzed, and the microstructure characteristics of the LaNi<subscript>5</subscript> and LaNi<subscript>4.5</subscript>Cu<subscript>0.5</subscript> systems at different stages of activation were determined. The pressure-composition isotherms were plotted, and the enthalpies of phase transitions α→β and β→α were calculated. The effect of substitution on the change in the thermodynamic parameters and microstructure characteristics of the hydride-forming intermetallic compounds during activation was shown.