Фазовая диаграмма системы Na-Te

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Na-Te (Sodium-Tellurium) A.D. Pelton and A. Petric The assessed phase diagram for the Na-Te system is based on [89Pet], with review of the data of [29Kra1] and [29Kra2]. The solid solubility of Na in (Te) or of Te in (Na) is expected to be very slight because of the large difference in chemical nature and crystal structure between Na, which is metallic, and Te, which is a metalloid. The limiting slope of the liquidus at 0 at.% Na, when calculated thermodynamically from the enthalpy of fusion of Te under the assumption of negligible solid solubility, agrees very well with the reported limiting liquidus slope in the assessed diagram. The liquidus for Te content from 0 to 33 at.% has been drawn with a pronounced S shape, which suggests a strong tendency to immiscibility between liquid Na, which is metallic, and liquid Na2Te, which probably has an ionic character. Such S-shaped liquidus curves have been observed at high alkali contents in the very similar Bi-K and Bi-Rb systems. The Li-Te phase diagram [73Cun] has been reported to have a region of liquid immiscibility over the approximate range from 5 to 25 at.% Te between the compound Li2Te and (Li). It is quite possible that a similar region of liquid immiscibility occurs in the Na-Te system. The stoichiometry of the compound NaTe has not been confirmed. However, its liquidus curve, when extended, passes through a maximum very near 50 at.% Te, indicating that the compound must have approximately this stoichiometry. 29Kra1: C.A. Kraus and S.W. Glass, J. Phys. Chem., 33, 984-994 (1929). 29Kra2: C.A. Kraus and S.W. Glass, J. Phys. Chem., 33, 995-999 (1929). 34Zin: E. Zintl, A. Harder, and B. Dauth, Z. Elektrochem., 40, 588-593 (1934) in German. 39Kle: W. Klemm, H. Sodomann, and P. Langmesser, Z. Anorg. Chem., 241, 281-304 (1939) in German. 70Fin: V.K. Finogenova, B.A. Popovkin, and A.V. Novoselova, Russ. J. Inorg. Chem., 15(6), 749-751 (1970). 70Wal: R.A. Walker and J.N. Pratt, J. Nucl. Mater., 34, 165-173 (1970). 73Cun: P.T. Cunningham, S.A. Johnson, and E.J. Cairns, J. Electrochem. Soc., 120, 328-330 (1973). 89Pet: A. Petric and A.D. Pelton, Ber. Bunsenges. Phys. Chem., 93, 18-24 (1989) . Submitted to the APD Program. Complete evaluation contains 1 figure, 3 tables, and 21 references. Special Points of the Na-Te System