Фазовая диаграмма системы Co-Ge

К оглавлению: Другие диаграммы (Others phase diargams)


Co-Ge (Cobalt-Germanium) K. Ishida and T. Nishizawa The assessed phase diagram for the Co-Ge system is based on [49Pfi], [80Day], and [90Eno], with review of the data of [52Kos], [73Aga], and [76Bal]. The equilibrium phases are (1) the liquid, L; (2) the Co-rich fcc terminal solid solution, (aCo); (3) the Co-rich cph terminal solid solution, (eCo); (4) Co3Ge, formed below about 770 C; (5) the hexagonal phase, Co5Ge2, stable between 636 and 382 C; (6) Co5Ge3, with two modifications: the high- temperature form, b (hexagonal), stable up to the congruent melting temperature of 1210 C, and the low-temperature form, a (orthorhombic), stable below about 385 C; (7) the monoclinic intermediate phase, CoGe, stable up to the peritectic temperature of 985 C; (8) the tetragonal phase, Co5Ge7, stable up to the peritectoid temperature of 806 C; (9) the orthorhombic phase, CoGe2, stable up to the peritectic temperature of 832 C; and (10) the cubic solid solution, (Ge), with negligible solid solubility of Co. [63Luo] reported that (aCo) or (eCo) solid solutions were obtained with up to 17.4 at.% Ge by rapid quenching from the melt, which yields a slight increment in the solubility limit of (aCo). Short-range ordering in amorphous films of CoGe2 and Co5Ge3 prepared by sputtering were studied by electron diffraction [75Gel, 75Lev1]. [75Lev2] conducted a similar study for amorphous films of CoGe, Co0.1Ge0.9, and Co5Ge3. An estimation of the glass transition temperature for the eutectic composition was reported by [79Nie]. The martensitic transformation, (aCo) = (eCo), has been studied by [52Kos] and [70Kra], and the transformation temperatures are reported in the complete evaluation. The reverse temperatures on heating are remarkably raised by the addition of Ge. The Curie temperature, TC, of the (aCo) phase was determined by [52Kos]. [ 52Kos] also reported that the TC of (eCo) in Co-12.5 at.% Ge alloy is 760 C, which is about 40 C higher than that of (aCo) at the same composition. Magnetic susceptibility was measured for Co-(36.0 to 40.5) at.% Ge alloys [ 73Aga], liquid Co-(8.3 to 66.7) at.% Ge alloys [73Zav], and Co-(0 to 38.5) at.% Ge alloys at 900 to 1800 C [75Dov]. 49Pfi: H. Pfisterer and K. Schubert, Z. Metallkd., 40, 378-383 (1949) in German. 50Sch: K. Schubert and H. Pfisterer, Z. Metallkd., 41, 433-441 (1950) in German. 52Kos: W. K”ster and E. Horn, Z. Metallkd., 43, 333-334 (1952) in German. 56Hel: E. Hellner, Z. Krist., 107, 99-123 (1956) in German. 60Bha: S. Bhan and K. Schubert, Z. Metallkd., 51, 327-339 (1960) in German. 63Luo: H. Luo and P. Duwez, Can. J. Phys., 41, 758-761 (1963). 69Pan: P.K. Panday and K. Schubert, J. Less-Common Met., 18, 175-202 (1969) in German. 70Kra: W. Krajewski, J. Kruger, and H. Winterhager, Cobalt, 48, 120-128 (1970) in German. 71Wal: F. Wald and S.J. Michalik, J. Less-Common Met., 24, 277-289 (1971). 73Aga: T.P. Agalakova, V.L. Zagryzhskii, and P.V. Geld, Izv. Akad. Nauk SSSR, Neorg. Mater., 9, 1180-1185 (1973) in Russian; TR: Inorg. Mater. (USSR), 9, 1048-1051 (1973). 73Zav: V.K. Zavyalov, I.Z. Radovskiy, E.S. Levin, Z.G. Nevzorova, and P.V. Geld, Izv. Akad. Nauk SSSR, (6), 32-34 (1973) in Russian; TR: Russ. Metall., ( 6), 18-20 (1973). 75Dov: S.P. Dovgopol, V.A. Anteropov, I.Z. Radoviskii, and P.V. Geld, Phys. Status Solidi (b), 70, 439-449 (1975). 75Gel: P.V. Geld, E.S. Levin, I.A. Pavars, and V.P. Jakubchik, Phys. Status Solidi (a), 30, 791-800 (1975). 75Lev1: E.S. Levin, P.V. Geld, V.P. Yakubchik, and I.A. Pavars, Kristallografiya, 20, 452-454 (1975) in Russian; TR: Sov. Phys. Crystallogr., 20, 278-279 (1975). 75Lev2: E.S. Levin, V.P. Yakubchik, and P.V. Geld, Kristallografiya, 20, 995- 999 (1975) in Russian; TR: Sov. Phys. Crystallogr., 20, 610-613 (1975). 76Bal: J.B. Ballanceand H. Stadelmaier, Z. Metallkd., 67, 729-731 (1976). 76Ell: M. Ellner, J. Less-Common Met., 48, 21-52 (1976) in German. 79Gel: P.V. Geld, E.S. Levin, V.L. Zagryazhskii, and V.N. Zamaraev, Izv. Akad. Nauk SSSR, Neorg. Mater., 15(1), 21-24 (1979) in Russian; TR: Inorg. Mater. USSR, 15(1), 14-17 (1979). 79Nie: N.J.V. Nielsen, Z. Metallkd., 70, 606-608 (1979). 80Day: A. Dayer and P. Feschotte, J. Less-Common Met., 72, 51-70 (1980) in French. 82Lar: V.I. Larchev and S.V. Popova, J. Less-Common Met., 87, 53-57 (1982). 83Nis: T. Nishizawa and K. Ishida, Bull. Alloy Phase Diagrams, 4, 387-390 ( 1983). 90Eno: H. Enoki, K. Ishida, and T. Nishizawa, J. Less-Common Met., 160, 153- 160 (1990). Submitted to the APD Program. Complete evaluation contains 1 figure, 8 tables, and 33 references. Special Points of the Co-Ge System