A Contribution to the Study of the Alloying Behaviour of the Rare Earths with Tin

The general alloying behaviour of tin with the rare earths was summarized on the base of the available literature data. A re-examination of the La? Sn alloys has been performed using x-ray and metallographic analyses. The existence of the following phases has been observed or confirmed: . The formation heats of the La? Sn alloys have been measured using a direct isoperibol calorimeter. The values of ΔH_form (solid alloys, room temperature, K cal/g atom) are the following: . A re-examination of the Y? Sn alloys has been also carried out confirming the existence and the crystal structures of the following phases: Y₅Sn₃, Y₅Sn₄, Y₁₁Sn₁₀, YSn₂ and YSn₃. A few calorimetric measurements performed on selected Sn-rich alloys have given the following values of the ΔH_form: YSn₂ (?15.5 ± 1.0 Kcal/g atom), YSn₃ (?12.5 ± 0.5 Kcal/g atom). The results obtained are discussed briefly and are compared with the data available for other rare earth-tin alloys.