Short- and intermediate-range order in amorphous GeTe

We have investigated amorphous GeTe by anomalous X‐ray scattering coupled with reverse Monte Carlo modeling. Experiments were conducted at the two K‐absorption edges in order to determine differential structure factors for both elements. The results indicate that simple models like the 8−N bonding rule cannot accurately rationalize the atomic structure. Te atoms are found to be over‐coordinated with a mean coordination number of about 2.5. Moreover, evidence is given for a high level of intermediate‐range order based on Ge, which has not been reported previously. This order has a pronounced effect on the ring statistics observed in the amorphous network, and thereby on the phase‐change speed of GeTe.