REVISED POURBAIX-DIAGRAMS FOR NICKEL AT 25-300-DEGREES-C

The Pourbaix diagrams (potential-pH diagrams) for nickel at 25-300 deg rees C have been revised. Extrapolation of thermodynamic data to eleva ted temperatures have been performed with the revised model of Helgeso n-Kirkham-Flowers, which also allows uncharged aqueous complexes, such as Ni(OH)(2)(aq), to be handled. Calculated high temperature thermody namic data have been checked and fitted against experimental data at e levated temperatures. The stable solid compounds of nickel are NiH0.5, beta-Ni(OH)(2)/NiO, and the higher oxides (beta and gamma phases). (C ) 1997 Elsevier Science Ltd.