Observation of the amorphous‐crystalline phase transition in the Ovonic semiconducting glass Te81Ge15As4 by the Mössbauer effect in Te125 and I129

Mössbauer spectra obtained with absorbers of Te12581Ge15As4 and a ZnTe125m source indicate that tellurium atoms are in an environment similar to that in tellurium metal. These spectra as well as those obtained with sources of Te129m81Ge15As4 and a CuI129 absorber indicate that the amorphous phase has a higher charge asymmetry than the crystalline phase which is consistent with the concept of ``dangling'' chemical bonds. Because of the great difference in the I129 spectra of the amorphous and crystalline phases it appears of interest to investigate Ovonic devices prepared with Te129m in order to see if voltage‐dependent phenomena can be observed in the I129 Mössbauer spectra