Фазовая диаграмма системы As-Sn

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As-Sn (Arsenic-Tin) N.A. Gokcen The As-Sn phase diagram is based on the data of [11Par], [12Par], [23Man], and [69Per]. The equilibrium phases are (1) the liquid; L; (2) the terminal solid solution, (As); (3) the line compounds AsSn and As3Sn4; and (4) the terminal solid phase (Sn), which is virtually pure tin. A limited solid solubility of Sn in As3Sn4+x determined by [74Vdo] is not in agreement with the results of [11Jol], [69Per], and [77Zal]; therefore, it is shown as a dashed line in the assessed diagram. Rhombohedral aAs dissolves about 3 с 2 at.% Sn at 700 C as estimated from thermodynamic equations. A similar thermodynamic estimate indicates that the solid solubility at 579 C is less than 10 at.% Sn, but in view of a solid solubility of 22 at.% Sn at all temperatures below 579 C estimated by [23Man], 15 at.% Sn is given here as a compromise. It is possible that the maximum solubility might be considerably less than 10 at.% Sn. Data on solubilities of elements in solid (As) are scarce, and available data on a few systems indicate very small solubilities. A value of 4 at.% Sn at 400 C is a very rough estimate in the assessed diagram. The solubility of Sn in As3Sn4 is probably small, as indicated by the lower eutectic temperatures of [69Per] near the stoichiometric compound. However, [ 74Vdo] showed that the solubility of Sn corresponds to 57.1 to 60 at.% Sn at 500 C, and the diagram indicates less than 59 at.% Sn at approximately 300 C. The experimental data are limited to 500 to 605 C. Although [68Eck] indicated solubilities of As in As3Sn4, it is not possible to determine the homogeneity range of this compound without further research. No metastable phase was found in the published investigations on this system. However, (bSn) is easily retained below 13 C at moderate rates of cooling, and remains as a metastable phase down to 0 K. 11Jol: P. Jolibois and E.L. Dupuy, Compt. Rend., 152, 1312-1314 (1911) in French. 11Par: N. Parravano and P. de Cesaris, Atti. Acad. Lincei, 20(1), 593-596 ( 1911) in Italian. 12Par: N. Parravano and P. de Cesaris, Gazz. Chim. Ital., 42(1), 274-283 (1912) in Italian; Intern. Z. Metallog., 2, 1-12 (1912) in German. 23Man: Q.A. Mansuri, J. Chem. Soc. (London), 123, 214-223 (1923). 68Eck: P. Eckerlin and W. Kischio, Z. Anorg. Allg. Chem., 363, 1-9 (1968) in German. 69Per: E.A. Peretti and J.K. Paulsen, J. Less-Common Met., 17, 283-290 (1969). 74Vdo: T.Z. Vdovina and Z.S. Medvedeva, Z. Neorg. Khim., 19(8), 2257-2260 ( 1974) in Russian. 77Zal: E. Zaleska, Rocz. Chem., 51(5), 849-853 (1977). Published in Bull. Alloy Phase Diagrams, 11(3), Jun 1990. Complete evaluation contains 4 figures, 4 tables, and 23 references. Special Points of the As-Sn System