PHASE-EQUILIBRIA AND CRYSTALLINE-STRUCTURE OF THE TB-CU-AL COMPOUNDS CONTAINING UP TO 50 AT-PERCENT TB

The Tb - Cu - Al phase diagram at 650 and 400 degrees C (aluminum-rich field) has been constructed on the basis of X-ray diffractometric dat a. The boundaries of solid solutions and the fields of the homogeneity of ternary compounds have bean determined. The mode of the distributi on of Cu and Al atoms in the TbCu5-based solid solution and in the TbC u12-xAlx ternary compound has been established. The crystalline struct ures of new compounds TbCu6.4Al4.6 (own structural type) and Tb3Cu1.2A l9.8 (structural type of La3Al11) have been determined.