Фазовая диаграмма системы Si-Ta

К оглавлению: Другие диаграммы (Others phase diargams)

Si-Ta (Silicon-Tantalum) M.E. Schlesinger The assessed Ta-Si phase diagram is based primarily on the work of [81Koc], who used metallographic, X-ray, and differential thermal analysis to investigate the system. Most of the experimental work in this system was performed at high temperatures, and eutectoidal decompositions of some phases at low temperatures cannot be ruled out. Measurements of the solubility of Si in (Ta) were made by [53Now] and [81Koc], with the latter results indicating a greater solubility range. The higher purity of the components used by [81Koc] recommend its adoption for this portion of the diagram. No disagreement has been expressed with the report by [ 54Bur] that the solubility of Ta in (Si) is negligible. Although not confirmed as such in purer Ta-Si alloys, the form of Ta4.5Si reported by [53Kie] and [53Now] appears to have been a metastable crystalline phase, requiring some level of interstitial impurity content to stabilize it [ 56Bre]. The same is apparently true of a hexagonal structure for Ta5Si3 reported by [53Now] and recently duplicated by [88Jia] during the crystallization of a co-sputtered amorphous Ta-Si thin film. The amorphous films generated by [88Jia] commonly are produced in several transition metal- silicon systems and were also created for tantalum silicides by [84Tu] and [ 87Nav]. Magnetic susceptibility measurements by [58Rob] showed that TaSi2 is diamagnetic, although less so than several other disilicides. Electrical resistivity measurements proved that this compound is metallic in character at ordinary temperatures [58Rob, 63Bri, 89Nav], although it may be of some use in high-temperature thermoelectric conversion. Measurements of the magnetic/ electrical properties of the other tantalum silicides have apparently not been made. 41Wal: H.J. Wallbaum, Z. Metallkd., 33, 378-381 (1941). 53Kie: R. Kieffer, F. Benesovsky, H. Nowotny, and H. Schachner, Z. Metallkd., 44, 242-246 (1953) in German. 53Now: H. Nowotny, H. Schachner, R. Kieffer, and F. Benesovksy, Monatsh. Chem., 84, 1-12 (1953) in German. 54Bur: J.A. Burton, Physica, 20, 845-854 (1954). 55Par: E. Parthe, H. Nowotny, and H. Schmid, Monatsh. Chem., 86, 385-396 (1955) . 56Bre: L. Brewer and O. Krikorian, J. Electrochem. Soc., 103, 38-51 (1956). 58Rob: D.A. Robins, Philos. Mag., 3, 313-327 (1958). 61Now: H. Nowotny and E. Laube, Planseeber. Pulvermetall., 9, 54-59 (1961). 63Bri: L.H. Brixner, J. Inorg. Nucl. Chem., 25, 257-260 (1963). 65Ros: W. Rossteutscher and K. Schubert, Z. Metallkd., 56, 813-822 (1965) in German. 69Dea: D.K. Deardorff, R.E. Siemens, P.A. Romans, and R.A. McCune, J. Less- Common Met., 18, 11-26 (1969). 81Koc: Yu.A. Kocherzhinskii, O.G. Kulik, and E.A. Shishkin, Dokl. Chem., 261, 106-108 (1981) in Russian; TR: Dokl. Chem., 261, 464-465 (1981). 84Tu: K.N. Tu, T. Tein, and S.R. Herd, Electron Microscopy of Materials, W. Krakow, D.A. Smith, and L.W. Hobbs, Ed., Materials Research Society, Pittsburgh, 201-210 (1984). 87Nav: F. Nava, K.N. Tu, E. Mazzega, M. Michelini, and G. Queirolo, J. Appl. Phys., 61, 1085-1093 (1987). 88Eng: I. Engstr”m and B. L”nnberg, J. Appl. Phys., 63, 4476-4484 (1988). 88Jia: Y. Jiang and M. Junru, Mater. Process. Charact. VLSI, 1988 (ICMPC '88), Proc. Int. Conf., X.-F. Zong, Y.-Y Wang, and J. Chen, ed., World Scientific, Teaneck, NJ, 229-232 (1988). 89Nav: F. Nava, E. Mazzega, M. Michelini, O. Laborde, O. Thomas, J.P. Senateur, and R. Madar, J. Appl. Phys., 65, 1584-1590 (1989). Submitted to the APD Program. Complete evaluation contains 2 figures, 5 tables, and 32 references. Special Points of the Ta-Si System