Phase equilibria in the copper-cobalt-sulfur system

Abstract

Phase equilibria in the copper-cobalt-sulfur system have been determined by means of silica tube techniques between 400° and 900°C. Throughout this interval the Cu 2−xS solid solution containing up to 11 wt % Co, coexists with cobalt sulfides (CoS 2, Co 3S 4, Co 1−xS, Co 9S 8, Co 4S 3). Co 3S 4 accepts up to 20.5 wt % copper and CoS 2 up to 12 wt % copper into solid solution. The increase in unit cell dimensions of Co 3S 4 and CoS 2 when copper substitutes for cobalt has also been determined.