A reverse Monte Carlo study of a zinc–europium phosphate glass

Abstract

A combination of seven independent experimental functions obtained by X-ray diffraction and EXAFS from synchrotron radiation and neutron diffraction techniques were used as references in a reverse Monte Carlo simulation of a glassy sample of 0.1Eu(PO₃)₃–0.9Zn(PO₃)₂ composition. The final model shows that the phosphate chains essentially retain the structure they have in pure zinc metaphosphate, while zinc and europium ions are set among the chains, so enveloped that oxygens from the PO₄ groups create coordination cages. The zinc ions maintain the same environment they have in pure zinc metaphosphate. The europium sites are more complex, made up by a nearest neighbour shell of non-bridging oxygens, to which also a minor number of bridging oxygens contribute at longer distances.