Фазовая диаграмма системы Ge-Sc

К оглавлению: Другие диаграммы (Others phase diargams)

Ge-Sc (Germanium-Scandium) A.B. Gokhale and G.J. Abbaschian The assessed Sc-Ge phase diagram is based mainly on the work of [81Ere]. The Sc-Ge system is characterized by the presence of the intermediate phases Sc5Ge3, Sc5Ge4, Sc11Ge10, ScGe, and ScGe2. ScGe2 exhibits a superconducting transition temperature of ~1.3 K [58Mat]. [81Ere] further determined that Sc5Ge3 melts congruently, whereas the other phases form through peritectic reactions that occur at decreasing temperatures with increasing Ge content. In addition, there are two eutectic reactions involving (Sc) and Sc5Ge3 and (Ge) and ScGe2. A metatectic reaction at the (Sc) terminal solid solution is likely. The liquid in the system was partially determined by [81Ere]. As indicated by dashed lines in the assessed diagram, most of the liquidus remains undetermined. No thermodynamic data are available for the liquid solution; however, experimental solubility data [81Ere] indicate that it is exothermic. According to [81Ere], Ge has a maximum solid solubility of 2.7 at.% in (aSc) at the eutectic temperature of 1274 C, decreasing to almost nil at 900 C. They reported that the solid solubility of Sc in (Ge) is nil at all temperatures. 58Mat: B.T. Matthias, E. Corenzwit, and W.H. Zachariasen, Phys. Rev., 112, 89 ( 1958). 62Arb: J. Arbuckle and E. Parth‚, Acta Crystallogr., 15, 1205-1207 (1962). 64Sch: O. Schob and E. Parth‚, Monatsh. Chem., 95, 1466-1472 (1964) in German. 65Sch: O. Schob and E. Parth‚, Acta Crystallogr., 19, 214-224 (1965). 81Ere: V.N. Eremenko, I.M. Obushenko, Yu.I. Buranov, and K.A. Meleshevich, Dop. Akad. Nauk Ukr. RSR A, 4, 80-83 (1981) in Ukrainian. Published in Bull. Alloy Phase Diagrams, 7(6), Dec 1986. Complete evaluation contains 2 figures, 3 tables, and 11 references. Special Points of the Sc-Ge System