The phase diagram of the Ca-Ge system

The phase diagram of the Ca-Ge system has been investigated across the 0-70 at.% Ge range using differential thermal analysis, metallographic analysis, X-ray diffraction and electron microscopy. Four intermediate phases have been confirmed: Ca2Ge (anti PbCl2-type), Ca5Ge3 (Cr5B3-type), CaGe (CrB-type) and CaGe2 (CaSi2-type). Ca7Ge6, not previously known, is a new representative of the Ca7Sn6-type orthorhombic structure. Four eutectics occur in this system: at about 3 at.% Ge and 780 degreesC, 47 at.% Ge and 1155 degreesC, 66 at.% Ge and 840 degreesC, 76 at.% Ge and 745 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.