Constitution of iron-germanium system is discussed based on x-ray and magnetic studies, and a new phase diagram is proposed. Fe solid solution (α) ranges up to 20.4 at.% Ge at 710°C and to 21.3 at.% Ge at 520°C. Homogeneity range of the most iron rich compound (ε above 700°C and ε
1 below) are 23.8–26 at.% Ge at 710°C (ε) and 24.2–25.8 at.% Ge at 580°C (ε
1). At 50 at.% Ge, ξ phase has a narrow range below 700°C.
In α (b. c. c.) solid solution of iron, the saturation magnetization and Curie point decrease to 150 emu/g and 885°K respectively. Crystal structures of ε and ε
1 phases are Ni
3Sn (D0
19) and Cu
3Au (L1
2) type, and the saturation magnetization of both phases is about 150 emu/g, while the Curie points are 650°K for ε and 760°K for ε
1. ζ Phase has CoSn (B35) type of structure and is paramagnetic, the moment being 2.8μ
B/Fe. Magnetic interaction and magnetic structures are also discussed.
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