Фазовая диаграмма системы Ce-Fe

К оглавлению: Другие диаграммы (Others phase diargams)


Ce-Fe (Cerium-Iron) W. Zhang, G. Liu, and K. Han The assessed Fe-Ce phase diagram is based mainly on the experimental data of [ 87Zhu], with review of the work of [74Gsc] and [82Kub]. [61Gsc] conducted an early review of the system and reported the existence of two stable phases- cubic Fe2Ce with the C15, Cu2Mg structure and hexagonal Fe5Ce with the D2d, CaZn5 structure. Later work confirmed the existence of Fe2Ce, but not Fe5Ce, which was considered as Fe7Ce by many investigators. [70Bus] proved that this intermetallic compound should be Fe17Ce2. Consequently, it is generally agreed that the two stable intermetallic compounds in this system are Fe2Ce and Fe17Ce2. The solid solubility of Ce in (aFe) is 0.094 wt.% at 900 C, 0.088 wt.% at 850 C [87Zhu], and 0.047 с 0.004 wt.% for quasi-equilibrium state at room temperature [87Yan, 87Zha]. Additions of Ce increase the transformation temperature of dFe <259> gFe from 1394 to 1399 C and that of gFe <259> aFe from 912 to 925 C [87Zhu]. Fe17Ce2 occurs in two modifications-hexagonal and rhombohedral [70Bus]. The transition temperature has not been established, and it would probably be difficult to do so. The transformation temperature is reported by [82Par] to be below 800 C, because only the rhombohedral modification is found in alloys 10.5 at.% Ce quenched from 800 C. However, the transformation temperature is further estimated to be at least below 690 C [87Zhu], if such a transformation exists. Fe2Ce is formed peritectically and shows no significant homogeneity range [ 70Bus]. The eutectic point of 592 C and 83 at.% Ce is from [74Gsc]. [87Zha] confirmed the eutectic temperature, but proposed that the eutectic composition should be 83.3 at.%. Addition of Ce to Fe decreases the Curie temperature of aFe to 752 C [87Zhu]. An investigation using M”ssbauer effect and bulk magnetization on Fe17Ce2 with Th2Zn17 structure indicated an antiferromagnetic/ferromagnetic transition near 70 K and an antiferromagnetic/paramagnetic transition at about 270 K [70Bus, 82Kub]. [84Oes] reported the Curie temperature as 238 K. Fe2Ce is ferromagnetic with a Curie temperature of 230 K [70Bus, 82Kub]. 61Gsc: K.A. Gschneidner, Jr., Rare Earth Alloys, 186, Van Nostrand Publishing, Amsterdam (1961). 64Ray: A.E. Ray, K. Strnat, and D. Fekdmenn, Rare Earth Research, III, Gordon and Breach, New York, 443 (1964). 65Ray: A.E. Ray, Proc. Fifth Rare Earth Res. Conf., 45 (1965). 66Bus: K.H.J. Buschow, J. Less-Common Met., 11, 204 (1966). 68Joh: G. Johnson, D.H Wood, G.S. Smith, and A.E. Ray, Acta Crystallogr. B, 24, 274 (1968). 70Bus: K.H.J. Buschow and J.S. van Wieringen, Phys. Status Solidi, 42, 231 ( 1970). 74Gsc: K.A. Gschneidner, Jr. and K.A. Verkade, IS-RIC-7, Rare-Earth Inf. Center, Iowa State University (1974). 76Har: I.R. Harris and G. Longworth, J. Less-Common Met., 41, 175 (1975). 77Bus: K.H.J. Buschow, Rep. Prog. Phys., 40, 1179 (1977). 82Kub: O. Kubaschewski, Iron-Binary Phase Diagrams, Springer-Verlag, New York, 97 (1982). 82Par: H.K. Park, H.H. Stadelmaier, and L.T. Jordan, Z. Metallkd., 73(H6), 399 (1982). 84Oes: H. Oesterreicher and F.T. Parker, J. Appl. Phys., 55(12), 15 (1984). 87Yan: Y.X. Yan and F.Z. Zhang, Rare Met., 6(2), 131-136 (1987) in Chinese. 87Zhu: Y.Z. Zhuang, C.H. Wu, and Z.B. Shao, Rare Earth, 1, 16 (1987) in Chinese. Submitted to the APD Program. Complete evaluation contains 2 figures, 4 tables, and 28 references. Special Points of the Fe-Ce System