The phase relations in the system ZnAs2-Ge were investigated by differ
ential thermal analysis (DTA) and X-ray powder diffraction. Besides th
e known ternary compound ZnGeAs2, another ternary phase of the composi
tion Zn2Ge11As4 with disordered zincblende structure was found, which
was unknown until now. Since the eutectic and melting point of the new
ternary compound differ by only a few degrees, a complete interpretat
ion of the phase relations between 60 and 68 mol% is very complicated.
We assume that the phase Zn2Ge11As4 is accompanied by two eutectics.