Фазовая диаграмма системы Ba-Pt

К оглавлению: Другие диаграммы (Others phase diargams)


Ba-Pt (Barium-Platinum) H. Okamoto The assessed phase diagram for the Ba-Pt system is based primarily on [71Dmi]. The Ba-rich part of the Ba-Pt phase diagram is unknown. [71Sav] also proposed a diagram in the same composition range. Because of the strong asymmetry of the BaPt5 liquidus, which is thermodynamically unlikely, the diagram of [71Sav] is not accepted. The equilibrium phases of the Ba-Pt system are: (1) the liquid, L; (2) the bcc terminal phase, (Ba); (3) fcc Cu2Mg-type BaPt2; (4) hexagonal CaCu5-type BaPt5; and (5) the fcc terminal phase, (Pt). The congruent melting temperature of BaPt2 is 1820 C [71Dmi]. The congruent melting point of BaPt5 is 1850 C [71Dmi] or ~1820 C [71Sav]. The L = BaPt2 + BaPt5 eutectic point is at 77 at.% Pt and 1770 C [71Dmi]. [50Heu] reported that BaPt5 is stable only at high temperatures. However, [ 70Zhu] could not confirm the instability at low temperatures at least down to 700 C. [71Dmi] reported the L = BaPt5 + (Pt) eutectic point at 95 at.% Pt and 1730 C, whereas [71Sav] reported it at ~94 at.% Pt and 1640 с 25 C. 50Heu: T. Heumann, Nachr. Akad. Wiss. Gottingen, A, 2(1), 1-6 (1950) in German. 58Woo: E.A. Wood and V.B. Compton, Acta Crystallogr., 11, 429-433 (1958). 68Sch: H. Schulz, K. Ritapal, W. Bronger, and W. Klemm, Z. Anorg. Allg. Chem., 357(4-6), 299-313 (1968) in German. 70Zhu: N.N. Zhuravlev, N.P. Esaulov, and I.V. Rall›, Kristallografiya, 15(2), 374-376 (1970) in Russian; TR: Sov. Phys. Crystallogr., 15(2), 315-316 (1970). 71Dmi: V.N. Dmitrieva, N.P. Esaulov, N.N. Zhuravlev, and V.M. Rozhdestvenskii, Tr. Inst. Fiz. Met., 28, 58-68 (1971) in Russian. 71Sav: E.M. Savitskiy, V.P. Polyakova, and E.M. Khorlin, Izv. Akad. Nauk SSSR, Met., (1), 157-159 (1971) in Russian; TR: Russ. Met., (1), 107-108 (1970). Submitted to the APD Program. Complete evaluation contains 1 figure, 2 tables, and 6 references. 1