Contribution to the thermodynamics of the Co-Sn system

Abstract

Comments on the available topological and thermochemical data of the Co-Sn system have been done. Updated data have been used in order to obtain adjustable coefficients for phase diagram calculation. In the present work both CoSn 3 modifications are modelled as different phases. The binary melt and the Co-based phases with face centred cubic and hexagonal structures are modelled as substitutional solutions. The allotropie forms of tin (αSn, βSn) as well as the intermediate phases CoSn, CoSn2, αCoSn3 and βCoSn3 are modelled as stoichiometric compounds. The phases αCO2Sn3 and βCo2Sn3 are described by four sublattice model: (Co)1(Sn)1(Co,Va)0.5(Co,Va)0.5 in order to account for the order-disorder transition. Reasonable agreement has been obtained between the calculated and the selected experimental thermodynamic and phase equilibrium data.