Фазовая диаграмма системы Ge-Pd

К оглавлению: Другие диаграммы (Others phase diargams)


Ge-Pd (Germanium-Palladium) H. Okamoto The assessed Ge-Pd phase diagram is based primarily on thermal, metallographic, and X-ray investigations for 20 to 90 at.% Pd alloys reported by [74Kha]. The equilibrium phases are (1) the liquid, L; (2) the diamond cubic terminal phase, (Ge); (3) orthorhombic MnP-type GePd; (4) hexagonal Fe2P-type GePd2; (5) tetragonal Ge8Pd21; (6) hexagonal Ge9Pd25; (7) GePd3, with an unknown crystal structure; (8) cubic W-type bGePd5; (9) monoclinic aGePd5; and (10) the fcc terminal phase, (Pd). In [74Kha], GePd, GePd2, and "Ge2Pd5" (Ge8Pd21) were shown to have homogeneity ranges of about 1 to 2 at.%; in the assessed diagram, only the phases for which there is positive evidence are shown with homogeneity ranges. The "Ge2Pd5" identified by [50Pfi] and [74Kha] is actually Ge8Pd21, according to detailed crystal structure investigations of [77Mat]. High-temperature bGePd2 exists between 840 and 775 C [74Kha]. Because bGePd2 is a disordered phase, there must be some homogeneity range, and the stoichiometry is nominal. [63Sch] found this phase above ~740 C at about 84 at.% Pd. The high-temperature "GePd4" found by [50Pfi] could be this phase [ Shunk]. According to the composition dependence of the lattice parameter of (Pd) quenched from 847 C [81Ell], the solubility of Ge in (Pd) at this temperature (not shown in the phase diagram). 50Pfi: H. Pfisterer and K. Schubert, Z. Metallkd., 41(10), 358-367 (1950) in German. 53And: K. Anderko and K. Schubert, Z. Metallkd., 44(7), 307-312 (1953) in German. 63Sch: K. Schubert, K. Frank, R. Gohle, A. Maldonaodo, H.G. Meissner, A. Raman, and W. Rossteutscher, Naturwissenschaften, 50(2), 41 (1963) in German. 74Kha: K. Khalaff and K. Schubert, Z. Metallkd., 65(5), 379-382 (1974) in German. 75Wop: W. Wopersnow and K. Schubert, J. Less-Common Met., 41(1), 97-103 (1975) in German. 77Mat: P. Matkovic, W. Wopersnow, and K. Schubert, J. Less-Common Met., 56(1), 69-75 (1977) in German. 77Wop: W. Wopersnow and K. Schubert, J. Less-Common Met., 52(1), 1-12 (1977). 78Mat: T. Matkovic and K. Schubert, J. Less-Common Met., 58(1), 1-6 (1978) in German. 80Ell: M. Ellner and B. Predel, J. Less-Common Met., 76, 181-197 (1980) in German. 81Ell: M. Ellner, J. Less-Common Met., 78, P21-P32 (1981) in German. Submitted to the APD Program. Complete evaluation contains 1 figure, 2 tables, and 11 references. Special Points of the Ge-Pd System