X-ray diffraction inVestigation of the Y-Cu-Ga system alloys and R.E. Cu2,R.E.Ga2 sectians

Due to X-ray structural investigation the isothermal cross section of the state diagram of the Y-Cu-Ga system at 700 deg C with participation of 7 ternary compounds is plotted. For three of them crystal structure is determined: Y(Cusub(0.46)Gasub(0.54) of the ThMn12 type; Ysub(2)(Cusub(0.67)Gasub(0.33))sub(17)-ThZnsub(1.7); YCusub(0.5)Gasub(1.5)-CaInsub(2). Investigation of REM sections Cu2-REMGa2 has shown the existence of ternary solid solutions on the base of REMxCu2 up to the composition of REMx(Cusub(0.8)Gasub(1.2))sub(2) (REM=Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, ternary phase LaCusub(1.70-0.80)Gasub(0.30-1.20) and ternary phases with the structure of the CaIn2 type with the composition REM Cusub(0.5)Gasub(1.5) (REM=Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu). The structure of low temperature modification of EuGa2 (CeCu2 type) is determined, that forms a continuous series of solid solutions with EuCu2