ANTIMONY ACTIVITIES IN THE TERNARY NIAS-PHASE OF THE IN-NI-SB SYSTEM

Antimony vapor pressures were determined in the ternary In-Ni-Sb syste m along, an isopleth with x(In)/x(Ni)=1/9, using an isopiestic method. The measurements were made between 980 and 1350 K, covering a composi tion range 43-48 at% Sb, with a few samples at higher antimony content s. Thermodynamic activities and partial molar enthalpies of antimony w ere derived for the ternary zeta-phase which crystallizes in an NiAs-t ype structure. The composition dependence of the activities is given f or a temperature of 1173 K, and isoactivity curves are constructed for the same temperature. The variation of the antimony activity along th e zeta/(zeta+L) phase boundary is estimated. (C) 1998 Elsevier Science B.V.