LA AND CE-INCORPORATION EFFECTS ON THE SURFACE-PROPERTIES OF THE FLUORINATED (TI,ZR)(MN,CR,NI)(2) HYDRIDING ALLOYS

A small amount of La or Ce incorporation into AB(2) alloys as Ti1-x/2Z r1-x/2(La/Ce)(x) Mn0.8Cr0.8Ni0.4 compounds with x varying from 0.0 to 0.05 has been performed in order to improve the activation characteris tics of Ti-Zr based AB(2) hydriding alloys in gas-solid reactions. The fluorinated surface properties of these compounds have been investiga ted in addition to structural and compositional analysis by ESCA, EPMA , XRD and microscope observations. La or Ce-incorporation forms La or Ce-rich secondary phase homogeneously distributed both at the grain bo undaries of the original AB(2) phase and at the particle surface. Thes e secondary phases contribute to the significant improvement of the ac tivation characteristics. Copyright (C) 1996 Elsevier Science Ltd.