Computer modelling and EXAFS study of the disorder in Cd1-xPbxF2 mixed systems

We report molecular dynamics and EXFAFS studies of Cd0.4Pb0.6F2 mixed syste m. A striking feature of molecular dynamics studies in Cd0.4Pb0.6F2 is the mobility of F- ions below. T-c calculations of defect activation energies a nd plots of single ion trajectories in this compound show that fluorine ion s migrate predominantly by a near interstitialcy mode of migration. The res ults obtained from EXAFS studies on local environments around Cd and Pb cat ions in this system are consistent with the findings from computer simulati ons on radial distribution functions. The local environment of Pb2+ ions is more disordered than that of Cd2+ ions.