CRYSTALLIZATION KINETICS AND PHASE EVOLUTION IN AMORPHOUS SB-S-GE THIN-FILMS

Thin amorphous Sb-S-Ge films with compositions in the range 20-80 mol% Sb and 0-10 mol% Ge were prepared by an ion-beam-sputtering method. The effects of composition on the crystallization kinetics and phase evolution were investigated by means of differential scanning calorimetry, X-ray diffraction and transmission electron microscopy. Upon crystallization, samples with an antimony content below 40 mol% were transformed to a single phase of Sb2S3, while in samples with an antimony content above 40 mol% a two-phase mixture of antimony and Sb2S3 was developed. The addition of germanium favoured the formation of an antimony single phase. Analysis of the kinetic parameters of crystallization suggested that the short-range ordering in the amorphous phase depended on the composition of the samples.