Фазовая диаграмма системы Ag-Eu

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Ag-Eu (Silver-Europium) K.A. Gschneidner, Jr. and F.W. Calderwood The assessed Ag-Eu phase diagram is based on the work of [65Kos], with some modifications. The stoichiometry of the Eu-rich phase has been changed from Ag3Eu5 to Ag2Eu3, based on the work of [80Bus]. Also, the intermediate phase in which Eu atoms substitute for some of the Ag atoms, designated as Ag2Eu(Eu) by [65Kos], is shown as Ag2Eu. [70Mcm] found Ag5Eu to be the Ag-rich compound in the Ag-Eu system. The solubility of Eu in (Ag), 0.01 to 0.02 at.% Eu at 710 C as reported by [ 70Gsc], is so low that it has not been indicated in the assessed diagram. The Eu-rich side of the present diagram above 87 at.% Eu is drawn as dashed lines, because the only available datum for this region is the melting point of Eu. [65Kos] reported the existence of the following phases: Ag5Eu (peritectic formation at 722 C), Ag4Eu (melting point, 792 C), Ag2Eu(Eu) (melting point, 673 C), and Ag3Eu5 (peritectic formation at 570 C). The phase designated as Ag2Eu(Eu) was reported to have the orthorhombic CeCu2-type structure with some Eu atoms occupying Ag sites, making the actual composition correspond to Ag5Eu3. Four eutectics were also reported: (Ag)-Ag5Eu (710 C, 12.5 at.% Eu), Ag4Eu-Ag2Eu3 (699 C, 25.5 at.% Eu), Ag2Eu-AgEu (648 C, 48 at.% Eu), and Ag2Eu3-(Eu) (429 C, 79 at.% Eu). [79Bus] investigated several amorphous alloys of Eu and Ag made by melt- spinning compositions near the deep eutectics in the Eu-Ag phase diagram. X- ray diffraction films showed halos for various concentrations in the composition range between Ag19Eu81 and Ag82Eu18. Thermal stability of the amorphous Ag54Eu46 began to recrystallize at about 150 C. Ferromagnetic ordering occurred in the amorphous alloys, whereas both ferromagnetic and antiferromagnetic types of ordering took place in the crystalline compounds. 65Kos: W. Koster and J. Meixner, Z. Metallkd., 56, 695-703 (1965). 70Gsc: K.A. Gschneidner, Jr., O.D. McMasters, D.G. Alexander, and R.F. Venteicher, Metall. Trans., 1, 1961-1971 (1970). 70Mcm: O.D. McMasters, K.A. Gschneidner, Jr., and T.F. Venteicher, Acta Crystallogr., B26, 1224-1229 (1970). 79Bus: K.H.J. Buschow and W.W. van den Hoogenhof, J. Magn. Magn. Mater., 12, 123-126 (1979). 80Bus: K.H.J. Buschow, J.H. van Vucht, and W.W. van den Hoogenhof, J. Less- Common Met., 75, 17 (1980). Published in Bull. Alloy Phase Diagrams, 6(1), Feb 1985. Complete evaluation contains 1 figure, 1 table, and 13 references. 1