Modification of selenium–tellurium amorphous composition with iron using the mechanical alloying method

The mechanical alloying method was used to add Fe to the amorphous Se8Te2 alloy. The effect of mechanically alloying Fe with Se8Te2 on the optical properties of thin films of the resulting alloys was studied in the UV–VIS spectral region. Different models for the determination of the optical energy gap were reviewed and used to analyze the obtained data. The optical energy gap was found to increase with the Fe content. Values of the optical energy gap of the alloys under investigation were determined using three different methods and the relation between different measures of the optical gap is explored. The effect of annealing at temperatures below the glass transition temperatures was also investigated. The optical energy gap found to decreases with the annealing time revealing the increase of randomness as a result of thermal annealing.