THE 530 ISOTHERMAL SECTION OF THE PHASE DIAGRAM OF Gd-Mn-Ni TERNARY SYSTEM

The 530 isothermal section of the phase diagram of Gd-Mn-Ni ternary system has been investigated by X-ray powder diffraction, DTA, optical microscopy and scanning electron microscopy techniques. The phase diagram consists of 14 single-phase regions, 26 two-phase regions and 13 three-phase regions.The 14 single-phase regions are ct(Gd), x (Mn), 3 (Ni), 6 (GdMn2), s (Gd6Mn23), <|> (GdMn12), y (Gd3N i), r| (GdN i), v (GdN i 2), cp(GdNi3), K(Gd2Ni7), X(GdNi5). u.(Gd2Ni,7), and I (GdMnNi) ?The 26 two-phase regions are : X+ and y+rjoThe 13 three-phase are : X+U.+P, X+O+u., O+U.+X, O+X+K, O+K+e, 8+K+v, ^+v+v, V+8+^, s+^+5, ?+v+n, 5+i]+^, S+y+T], and 8+y+a.The ex i stence of 1 0 b i nary compounds and 1 ternary compound,namely Gd2Ni,7. GdNis, Gd2Ni7, GdNi3, GdNi2, GdNi, Gd,Ni, GdMn,2r Gd6Mn23 GdMn2 and GdMnNi, at 803k were confirmed, no new binary or ternary compound was found in this work.At 803K, the maximum sol id solubi I ity of Mn in Ni, Gd2Ni17, GdN i 5, Gd2N i 7. GdN i 3 . GdN i 2, GdN i and Gd3N i are about 31 at% Mn, 18 at% Mn, 13 at% Mn, 10 at% Mn, 8 at% Mn, 8 at% Mn, 4 at% Mn and 2 at% Mn, respect i ve I y. The maximum sol id solubi I ity of Ni i n Mn , GdMn,2, Gd6Mn23 and GdMn2, are 3 at% Ni,4 at% Ni,3 at % Ni and 5 at% Ni, respectively.At 803K, in the ?phase, Mn and Ni atoms can replace each other limitedly . There is a range extending from about 31at% Ni to 34 at% Ni in the ? phase.