Фазовая диаграмма системы Pt-Si

К оглавлению: Другие диаграммы (Others phase diargams)

Pt-Si

Pt-Si (Platinum-Silicon) H. Okamoto and L.E. Tanner The assessed Pt-Si phase diagram is based on [36Vor] and [64Goh], with review of the experimental data of [60Sch] and [69Gol]. Pt5Si2 [36Vor] and Pt7Si3 [ 64Goh] are identified as b- and aPt12Si5 in the assessed diagram. Pt4Si is an impurity-stabilized phase [64Goh, 78Ram]. The liquidus boundaries determined by [36Vor] essentially have been unchallenged. The assessed diagram differs from [36Vor] (see [Hansen]) only in the 25 to 30 at.% Si range, where the solid phases in equilibrium with L were studied later in more detail. The three eutectic temperatures in the assessed diagram are also as determined by [36Vor]. The temperature of the Pt-richest eutectic was confirmed by [57Rei]. The solid solubility of Si in (Pt) is about 1.4 at.% [36Vor]. [60Sch] found that the solid phase in equilibrium with (Pt) is Pt3Si, which was not observed by [36Vor]. [64Goh] found three polymorphic forms of Pt3Si. Another high-temperature phase was also observed by [64Goh], who considered it probably to be stabilized by impurity. Reinvestigation of these phases by [ 78Ram] indicated that in addition to this high-temperature phase, gPt3Si is also an impurity-stabilized phase. Accordingly, only two allotropic forms of Pt3Si are shown in the assessed diagram. The phases proposed earlier as Pt5Si2 (28.6 at.% Si) [36Vor] and Pt7Si3 (30 at. % Si) [64Goh] were identified as Pt12Si5 (29.4 at.% Si) [69Gol]. Two metastable phases, Pt2Si3 and Pt4Si9, were found to form by crystallization of amorphous Pt-Si alloys [79Tsa]. The transition temperatures are 390 and 400 C, respectively [80All]. The onset temperature of superconductivity in Pt2Si3 is 4.2 K [80Tsa]. 36Vor: N.M. Voronov, Izv. Sektora Platiny, 13, 145-166 (1936) in Russian. 50Pfi: H. Pfisterer and K. Schubert, Z. Metallkd., 41(10), 358-367 (1950) in German. 51Bud: J.H. Buddery and A.J.E. Welch, Nature, 167, 362 (1951). 57Rei: G. Reinacher, Rev. M‚tall., 54, 321-336 (1957) in French. 60Sch: K. Schubert, S. Bahn, W. Burkhardt, R. Gohle, H.G. Meissner, M. Potzschke, and E. Stolz, Naturwissenschaften, 47(13), 303 (1960) in German. 64Goh: R. Gohle and K. Schubert, Z. Metallkd., 55, 503-511 (1964) in German. 69Gol: W. Gold and K. Schubert, Z. Kristallogr., 128, 406-413 (1969) in German. 73Gra: E.J. Graeber, R.J. Baugham, and B. Morosin, Acta Crystallogr. B, 29(9), 1991-1994 (1973). 75May: H.W. Mayer and K. Schubert, Z. Metallkd., 66, 437 (1975) in German. 78Ram: R.P. Ram and S. Bhan, Z. Metallkd., 69, 524-529 (1978). 79Tsa: B.Y. Tsaur, Z.L. Liau, and J.W. Mayer, Phys. Lett. A, 71(2,3), 270-272 ( 1979). 80All: M. von Allmen, S.S. Lau, M. Maenpaa, and B.Y. Tsaur, Appl. Phys. Lett., 37(1), 84-86 (1980). 80Tsa: B.Y. Tsaur, J.W. Mayer, and K.N. Tu, J. Appl. Phys., 51(10), 5326-5333 ( 1980). Submitted to the APD Program. Complete evaluation contains 1 figure, 3 tables, and 19 references. Special Points of the Pt-Si System