Simultaneous crystallization of both elements in amorphous GeSb and GeAl eutectic alloys

Electron microscopic investigations have been carried out on the early stages of crystallization of amorphous eutectic GeSb and GeAl alloys with no intermediate compound. The GeSb and GeAl films, prepared by vacuum coevaporation on the substrates at room temperature, are amorphous for Ge concentrations larger than 0.1 and 0.5, respectively. The crystallization of these films are characterized by simultaneous formation of both constituents in their crystalline forms, adjacent each other with specific orientation relationships: (246)Ge (003)Sb and [032]Ge [110]Sb for GeSb, and (111)Ge (224)Al and [121]Ge [110]Al for GeAl. The crystallization temperature decreases monotoneously with increasing Sb or Al content, and is well fitted to 2 3 values of the liquids temperature in Kelvin in the case of GeSb.