The short and intermediate range order of an amorphous Ge$_{ 30}$Se$_{ 70}$ alloy produced by Mechanical Alloying were studied by Reverse Monte Carlo simulations of its x-ray total structure factor, Raman scattering and differential scanning calorimetry. The simulations were used to compute the $G^{ \text{ RMC}}_{ \text{ Ge-Ge}}(r)$, $G^{ \text{ RMC}}_{ \text{ Ge-Se}}(r)$ and $G^{ \text{ RMC}}_{ \text{ Se-Se}}(r)$ partial distribution functions and the ${ \cal S}^{ \text{ RMC}}_{ \text{ Ge-Ge}}(K)$, ${ \cal S}^{ \text{ RMC}}_{ \text{ Ge-Se}}(K)$ and ${ \cal S}^{ \text{ RMC}}_{ \text{ Se-Se}}(K)$ partial structure factors. We calculated the coordination numbers and interatomic distances for the first and second neighbors and the bond-angle distribution functions $\Theta_{ ijl}(\cos\theta)$. The data obtained indicate that the structure of the alloy has important differences when compared to alloys prepared by other techniques. There are a high number of Se-Se pairs in the first shell, and some of the tetrahedral units formed seemed to be connected by Se-Se bridges.
Categories: cond-mat.mtrl-sci