Systeme gallium-tellure

Three phases are present in the GaTe system: Ga 2 Te 5 , Ga 2 Te 3 , and GaTe. Ga 2 Te 5 is stable in a narrow temperature domain, between about 400 and 495°C (its peritectic decomposition). The phase diagram is established from DTA and X-ray diffraction studies. The crystal structures of GaTe and Ga 2 Te 5 are described. The first one contains GaGa pairs and the second one a square plane coordination of Te, in which the atoms are bonded by covalency. The formation of compounds involving monovalent Ga is discussed, in connection with the existence of SnGa 6 Te 10 , in which Sn can be substituted by other monovalent or divalent cations.