Фазовая диаграмма системы Ga-Li

К оглавлению: Другие диаграммы (Others phase diargams)

Ga-Li (Gallium-Lithium) J. Sangster and A.D. Pelton The assessed Ga-Li phase diagram is based on the experimental data of [70Thu], [73Yat], and [81Wen]. The eutectic between (Ga) and Ga14Li3 was reported at 27.5 C [73Yat] and ~26 C [70Thu]. From the thermodynamic equation for the limiting liquidus slope, under the assumption of negligible solid solubility of Li in (Ga), the eutectic liquid composition at 27.5 C is calculated at 1.7 at.% Li. Any solid solubility would shift this point to higher Li concentrations. Hence, the liquidus compositions of 1 and 2.5 at.% Li at 150 and 200 C, respectively, reported by [73Yat] are inconsistent with a eutectic temperature of 27.5 C. The liquidus (solubility) in the range 0 to 20 at.% Li should thus be assigned error bars of с2 at.%. Thermal analysis data indicate that the solid solubilities of Li in (Ga) and of Ga in (Li) are small. The low temperatures involved would also favor low solubility. On the other hand, the atomic radii of Li and Ga differ by only 3%, so some solid solubility should not be ruled out. There are apparently two peritectic transformations on the Ga-rich side of the phase diagram. Temperature arrests at 290 с 2 and 365 C were reported by [ 73Yat], who ascribed the lower peritectic to the compound Ga4Li [73Yat] or Ga3Li [77Yat] upon the basis of chemical analysis. For the higher peritectic, the compound Ga2Li was suggested on the bases of chemical analysis and additional lines in the X-ray patterns of mixtures from 30 to 35 at.% Li. In a study of single crystals of Ga14Li3 [82Bel], peritectics at 288.4 and 356.3 C were found. Because Ga14Li3 has been well characterized, it is reasonable to ascribe the lower transformation with a particularly large thermal effect [ 82Bel] to Ga14Li3. The exact stoichiometry of "Ga2Li" remains in doubt. The Ga-rich phase boundary of GaLi is essentially constant at 45 at.% Li from 390 to 585 C [81Wen]. The shape of the GaLi phase field as drawn in the assessed diagram is very similar to that of the AlLi phase field in the Al-Li system. 33Zin: E. Zintl and G. Brauer, Z. Phys. Chem. Abstr. B, 20, 245-271 (1933) in German. 70Thu: R. ThЃmmel and W. Klemm, Z. Anorg. Allg. Chem., 376(1), 44-63 (1970) in German. 73Yat: S.P. Yatsenko, K.A. Chuntonov, S.I. Alyamovsky, and E.N. Diyeva, Izv. Akad. Nauk SSSR Met., (1), 185-188 (1973) in Russian; TR: Russ. Metall., (1), 131-133 (1973). 77Mul: W. MЃller and J. St”hr, Z. Naturforsch. B, 32, 631-636 (1977) in German. 77Yat: S.P. Yatsenko, J. Chim. Phys., 74(7-8), 836-843 (1977). 81Bus: V.D. Bushmanov and S.P. Yatsenko, Zh. Fiz. Khim., 55(11), 2951-2952 ( 1981) in Russian; TR: Russ. J. Phys. Chem., 55(11), 1680-1681 (1981). 81Sto: J. St”hr and H. Sch„fer, Z. Anorg. Allg. Chem., 474, 221-225 (1981) in German. 81Wen: C.J. Wen and R.A. Huggins, J. Electrochem. Soc., 128(8), 1636-1641 ( 1981). 82Bel: C. Belin and R.G. Ling, J. Solid State Chem., 45(2), 290-292 (1982). 82Sto: J. St”hr and H. Sch„fer, Rev. Chim. Min., 19(2), 122-127 (1982) in German. Submitted to the APD Program. Complete evaluation contains 1 figure, 3 tables, and 13 references. Special Points of the Ga-Li System