Фазовая диаграмма системы Li-Si

К оглавлению: Другие диаграммы (Others phase diargams)


Li-Si (Lithium-Silicon) H. Okamoto The assessed Li-Si phase diagram is based essentially on a thermodynamic calculation, and is nearly identical with that of [85Mar]. Very little is known about the thermodynamic properties of the liquid phase. The liquidus boundaries in the assessed diagram are the result of the present thermodynamic calculations, except for the range between Li13Si4 and Li7Si3, where the calculated eutectic temperature is 719 C. The assessed temperature, 709 с 2 C, was adopted from [85Mar]. A calculated value for the eutectic composition, 25.1 at.% Si, is shown in the assessed diagram. A conspicuous disagreement between [85Mar] and the calculated diagram is found in the liquid composition of the L + Li13Si4 = Li22Si5 peritectic reaction. The calculated value is accepted in the assessed diagram, because the proposed value, 18 at.% Si, leads to an unusual curvature in the liquidus boundary. Assuming no solubility of Si in (bLi), the L = (bLi) + Li22Si5 eutectic point was calculated to be 0.004 at.% Si at a temperature 0.1 C below the melting point of Li. These values are based on various thermodynamic assumptions and have not been confirmed. Before Li22Si5 was found, Li4Si or Li15Si4 was considered to be the Li-richest compound. Because of persistent observations of Li4Si or Li15Si4 by [65Sch], [ 76Sha], and [80Nik], a phase with one of these formulas may exist in a limited temperature range or may be stabilized by impurity. 64Gla: E.I. Gladyeshevskii, G.I. Oleksiv, and P.I. Kripyakevich, Kristallografiya, 9(3), 338-341 (1964) in Russian; TR: Sov. Phys. Crystallogr., 9(3), 269-271 (1964). 65Sch: H. Schafer, H. Axel, and A. Weiss, Z. Naturforsch. B, 20(12), 1302 ( 1965) in German. 75Fra: U. Frank, W. Muller, and H. Schafer, Z. Naturforsch. B, 30(1), 10 (1975) in German. 76Sha: R.A. Sharma and R.N. Seefurth, J. Electrochem. Soc., 123(12), 1763-1768 (1976). 80Nik: V.P. Nikolaev, A.G. Morachevskii, A.I. Demidov, and E.V. Bairachnyi, Zh. Prikl. Khim., 53(9), 2088-2090 (1980) in Russian; TR: J. Appl. Chem. USSR, 53( 9), 1549-1551 (1981). 80Sch1: H.G. von Schnering, R. Nesper, J. Curda, and K.F. Tebbe, Angew. Chem. Int. Ed., 19(12), 1033-1034 (1980). 80Sch2: H.G. von Schnering, R. Nesper, K.F. Tebbe, and J. Curda, Z. Metallkd., 71(6), 357-367 (1980) in German. 85Mar: C. Van der Marel, G.J.B. Vinke, and W. Van der Lugt, Solid State Commun. , 54(11), 917-919 (1985). Published in Bull. Alloy Phase Diagrams, 11(3), Jun 1990. Complete evaluation contains 2 figures, 7 tables, and 44 references. Special Points of the Li-Si System