Фазовая диаграмма системы Au-Cl

К оглавлению: Другие диаграммы (Others phase diargams)

Au-Cl (Gold-Chlorine) H. Okamoto and T.B. Massalski The partial assessed Au-Cl phase diagram is based on the differential thermal analysis and high-temperature X-ray diffraction study of [76Jan]. The following phases have been reported: (1) the liquid, L; (2) the fcc terminal solid solution, (Au); (3) the tetragonal compound gold monochloride, AuCl; and (4) the monoclinic compound gold trichloride, AuCl3. The triple- and boiling- point temperatures of Cl are -100.97 C and -34.05 C, respectively. Pressure- dependent phase relationships near the (Cl) terminal phase are not known. According to [74Jan], the AuCl crystalline phase forms from Au2Cl6(s) at ~250 C via Au2Cl6(g) when the pressure of Cl2 gas is 1 atm. The same AuCl phase is also reported to form when AuCl3 is heated to 185 C [47Kir]. The peritectic formation of AuCl involving the liquid phase occurs under a Cl2 pressure of 3 atm at 342 C [76Jan], as shown in the assessed partial diagram. However, the AuCl compound is metastable at room temperature and decomposes via a eutectoid reaction at 90 с 35 C. 47Kir: R.E. Kirk and D.F. Othmer, Encyclopedia of Chemical Technology, Vol. 7, 1st ed., Interscience Publishers, New York, 285 (1947). 74Jan: E.M.W. Janssen, J.C.W. Folmer, and G.A. Wiegers, J. Less-Common Met., 38(1), 71-76 (1974). 76Jan: E.M.W. Janssen, F. Pohlmann, and G.A. Wiegers, J. Less-Common Met., 45( 2), 261-273 (1976). Published in Phase Diagrams of Binary Gold Alloys, 1987. Complete evaluation contains 1 figure, 4 tables, and 26 references. 1