Fe-Sb-Sn (iron-antimony-tin)
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Fe-Sb-Sn (Iron-Antimony-Tin) V. Raghavan
[1997Pav] determined an isothermal section at 200 ⬚C for this system. This section is characterized by the absence of ternary compounds.
the NaCl-type cubic structure and has a wide range of homogeneity.
Binary Systems
Ternary Isothermal Section
The Fe-Sb phase diagram reviewed by [1993Oka1] is accepted. See also the update by [1999Oka]. There are two intermediate phases in this system: , which has the NiAstype hexagonal structure, has a homogeneity range of 40 to 47 at.% Sb; and FeSb2 is a line compound and has the FeS2 (marcasite)-type orthorhombic structure [Pearson3, 1997Pav]. In the Fe-Sn system [1993Oka2], there are four intermediate phases: Fe5Sn3, Fe3Sn2, FeSn, and FeSn2. Some uncertainty exists regarding the composition and existence of the high-temperature phases of this system. At the temperature of our interest (200 ⬚C), only FeSn and FeSn2 are stable. FeSn has the CoSn-type hexagonal structure and FeSn2 has the CuAl2-type tetragonal structure. [1995Oht], during the course of their study of the Pb-Sb-Sn ternary system, experimenally investigated and also computed the Sb-Sn phase diagram. The only intermediate phase of the system  has
[1997Pav] melted 43 alloys in an arc furnace under Ar atm. The alloys were annealed at 200 ⬚C for 400 h. The phase equilibria were studied by x-ray powder diffraction. The isothermal section of [1997Pav] at 200 ⬚C is redrawn in Fig. 1 to agree with the accepted binary data. The close atomic radii of Sb and Sn and similar electronic structure result in appreciable substitution of each other at constant Fe content in the Fe-Sb and Fe-Sn compounds. The extent of this solubility and the corresponding changes in the lattice parameters are listed in Table 1 from [1997Pav]. The Sb-Sn compound  dissolves an insignificant amount of Fe. References 1993Oka1: H. Okamoto: Phase Diagrams of Binary Iron Alloys, ASM International, Materials Park, OH, 1993, pp. 366-70.
Fig. 1 Fe-Sb-Sn isothermal section at 200 ⬚C [1997Pav]
Journal of Phase Equilibria Vol. 22 No. 6 2001
669
Section II: Phase Diagram Evaluations Table 1 Fe-Sb-Sn crystal structure and lattice parameter data Composition, at.% Sn
Sb
Pearson symbol
Space group
Strukturbericht designation
Prototype
0-20
45-24
hP4
P63/mmc
B81
NiAs
FeSn1⫺xSbx
50-40
0-10
hP6
P6/mmm
B35
CoSn
FeSb2⫺xSnx
0-11.7
66.7-55
oP6
Pnnm
C18
FeS2 (marcasite)
FeSn2⫺xSbx
66.7-51.7
0-15
tI12
I4/mcm
C16
CuAl2
Phase
1993Oka2: H. Okamoto: Phase Diagrams of Binary Iron Alloys, ASM International, Materials Park, OH, 1993, pp. 385-92. 1995Oht: H. Ohtani, K. Okuda, and K. Ishida: J. Phase Equilibria, 1995, vol. 16 (5), pp. 416-29.
670
Lattice parameter, nm a c a c a b c a c
⫽ ⫽ ⫽ ⫽ ⫽ ⫽ ⫽ ⫽ ⫽
0.4065 0.5121 0.5288 0.4420 0.5834 0.6530 0.3193 0.6542 0.5386
⫺ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺
0.4138 0.5169 0.5274 0.4412 0.5890 0.6598 0.3265 0.6451 0.5292
1997Pav: V.V. Pavlyuk, O.I. Bodak, A. Stowinska, D.G. Kevorkov, and G.S. Dmytriv: Polish J. Chem., 1997, vol. 71, pp. 11-15. 1999Oka: H. Okamoto:
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