Phase equilibria in the Tb-Ti-Ge system at 1070 K

Physico-chemical analysis techniques, including X-ray phase analysis, electron probe X-ray analysis, differential thermal analysis and metallographic analysis were employed in constructing the isothermal section of the Tb-Ti-Ge system at 1070 K. The formation of the following ternary intermetallic compounds were detected in the Tb-Ti-Ge system at 1070 K: TbTiGe thigh-temperature modification of CeFeSi structure type, space group P4/nmm, a = 0.4050(2) nm, c = 0.7652(3) nm: low-temperature modification of La2Sb structure type, space group I4/mmm, a = 0.4053(2) nm, c = 1.5293(3) nm) and Tb22...15Ti34...41Ge44 (Sm5Ge4 structure type, space group Pnma, a = 0.7019(1)...0.6889(5) nm, b = 1.3457(2)...1.332(1) nm, c = 0.7156(1)...0.755(1) nm). The TbGe3.5 compound belongs to the ThGe2 structure type (space group Cmmm, a = 2.0738(4) nm, b = 0.4043(1) nm, c = 0.3914(1) nm). The high-temperature modification of the Th2Ge3 compounds belongs to the ThSi2 structure type (space group I4(1)/amd, a = 0.4061(2) nm, c = 1.372(1) nm). (C) 1998 Elsevier Science S.A. All rights reserved.