Фазовая диаграмма системы Ga-Yb

К оглавлению: Другие диаграммы (Others phase diargams)

Ga-Yb (Gallium-Ytterbium) A. Palenzona and S. Cirafici The assessed Ga-Yb phase diagram is based primarily on [79Pal] and [81Pel], with review of the experimental data of [77Yat], [78Yat], and [79Yat]. The temperatures reported by [78Yat] are systematically 20 to 30 C higher than those reported by [79Pal] except that for the Yb-rich eutectic. The melting point and transformation temperatures of pure elements have been corrected to the currently accepted values. The equilibrium phases of the Ga-Yb system are ( 1) the liquid, L; (2) the five intermediate phases, Ga6Yb, Ga4Yb, Ga2Yb, GaYb, and GaYb2; and (3) the two terminal solid solutions, (aGa) and (Yb), with negligible solubility. [79Pal] showed four intermetallic phases: Ga4Yb (peritectic melting at 755 C) and Ga2Yb, GaYb, and GaYb2 (congruent melting at 1100, 895, and 655 C, respectively). Four eutectic points were present at 78.5 at.% Yb and 605 C, 66.0 at.% Yb and 650 C, 46.5 at.% Yb and 880 C, and >1.0 at.% Yb and 27 C. The transformation temperatures of Yb seemed to be unaffected by Ga; no extended terminal solubility was found, as the lattice parameters of pure elements did not change significantly when alloyed with one another. [81Pel], in a careful investigation of the Ga-rich side of the RE-Ga systems, found a new Ga-rich phase Ga6RE, common to almost all rare earths, corresponding to the Ga6Pu structure type. In the Ga-Yb system, Ga6Yb is formed by a peritectic reaction at 282 C. [64Ian] measured the magnetic susceptibility of Ga2Yb in the range 80 to 500 K and showed Yb to be in the divalent state in this temperature range. [79Pal] examined the magnetic properties of the Ga-Yb compounds at room temperature and found that Ga4Yb, Ga2Yb, GaYb, and GaYb2 contain divalent Yb. [86Tag] studies the magnetic properties (4.2 to 300 K) and the electrical resistivity (1.7 to 300 K) of Ga6RE phases. Ga6Yb is a Pauli paramagnet but shows anomalous resistivity. The existence of an Al4Ba-type phase should be confirmed, and the crystal structure and composition of other phases close to this stoichiometry require investigation. It is possible that two phases are formed in a very narrow range of composition, perhaps with minor structural and temperature-dependent modifications. 64Ian: A. Iandelli, Z. Anorg. Allg. Chem., 330, 221-232 (1964) in German. 65Kri: P.I. Kripyakevich, E.I. Gladishevskii, and D.I. Dzyana, Kristallografiya, 10(4), 471-473 (1965) in Russian. 77Yat: S.P. Yatsenko, J. Chim. Phys., 74(7-8), 836-843 (1977). 78Yat: S.P. Yatsenko, B.G. Semenov, and K.A. Chuntonov, Izv. Akad. Nauk SSSR, Met., 1, 193-194 (1978) in Russian. 79Pal: A. Palenzona and S. Cirafici, J. Less-Common Met., 63, 105-109 (1979). 79Yat: S.P. Yatsenko, A.A. Semyannikov, B.G. Semenov, and K.A. Chuntonov, J. Less-Common Met., 64, 185-199 (1979). 81Pel: J. Pelleg, G. Kimmel, and D. Dayan, J. Less-Common Met., 81, 33-44 ( 1981). 86Tag: Y. Tagawa, J. Sakurai, Y. Komura, and T. Ishimasa, J. Less-Common Met., 119, 269-275 (1986). Submitted to the APD Program. Complete evaluation contains 1 figure, 3 tables, and 9 references. Special Points of the Ga-Yb System