Фазовая диаграмма системы Co-Mg

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Co-Mg (Cobalt-Magnesium) A.A. Nayeb-Hashemi and J.B. Clark Only the Mg-rich region of the Mg-Co system has been well established, but there is general agreement [35Wet, 47Cra, 64Smi] that Co lowers the melting point of Mg to a eutectic point. The assessed phase diagram is based primarily on the work of [64Smi]. Co has two allotropic modifications that commonly coexist at room temperature. eCo is stable from -273 to 422 C and has a hexagonal structure, isotypic with Mg; aCo is stable from 422 to 1495 C (melting point) and has the fcc structure. The solid solubility of Co in (Mg) is negligible. There is also no appreciable solid solubility of Mg or Co in the MgCo2 compound, or of Mg in (Co). [75Bus] measured the magnetic properties of MgCo2 and found it to be ferromagnetic below 321 K, undergoing a first-order ferromagnetic antiferromagnetic transition near 45 K. [81Bus] prepared amorphous alloys of Mg-Co in the composition range 30 to 90 at.% Co by two-source evaporation and found that these amorphous alloys showed ferromagnetic behavior, in which the Co moment decreased with decreasing Co content. 35Wet: J.P. Wetherill, Metals and Alloys, 6, 153-155 (1935). 47Cra: E.M. Cramer, H.P. Nielsen, and F.W. Schonfeld, Light Metal Age, 5, 6-9 ( 1947). 64Smi: J.F. Smith and M.J. Smith, Trans. Q. ASM, 57, 337-345 (1964). 75Bus: K.H.J. Buschow, Solid State Commun., 17, 891-893 (1975). 81Bus: K.H.J. Buschow and P.G. VanEngen, Solid State Commun., 39, 1-3 (1981). Published in Phase Diagrams of Binary Magnesium Alloys, 1988, and Bull. Alloy Phase Diagrams, 8(4), Aug 1987. Complete evaluation contains 1 figure, 3 tables, and 14 references. 1