RMC - MODELING NEUTRON-DIFFRACTION, X-RAY-DIFFRACTION AND EXAFS DATA SIMULTANEOUSLY FOR AMORPHOUS MATERIALS

The simultaneous modelling of neutron diffraction, X-ray diffraction and extended X-ray absorption fine structure (EXAFS) data for a disordered material has been developed with the reverse Monte Carlo (RMC) method. The details of this technique are described and its power is highlighted by modelling four sets of experimental data simultaneously for the multi-component, amorphous fast-ion conductor (AgI)(x)(AgPO3)(1-x). From the resultant structural models, it is proposed that the first sharp diffraction peak observed in the diffraction data at Q similar or equal to 0.7 Angstrom(-1) is related to the density distribution of the phosphate network; pathways through the structure which favour Ag+ ion conduction are highlighted and a structural explanation for the material's glass formation limit at x approximate to 0.58 is proposed.