Simulation of PbWO4–PbMoO4 Solid Solutions by the Method of Interatomic Potentials

The PbW _1-x MoxO4 solid solutions were simulated by the method of empirical interatomic potentials. The mixing functions of the volume and the enthalpy show deviations from the additivity, indicating that the solid solution is non-ideal. The investigation of the local environment of the ions demonstrated that the size of PbО8 polyhedra increases with increasing molybdenum content in the solid solution, and these polyhedra are significantly distorted in intermediate compositions. The МоО4 and WO4 tetrahedra are more stable; however, their sizes also slightly decrease with increasing concentration of molybdenum, and these tetrahedra are also distorted in intermediate compositions. The changes in the local structure of the solid solutions lead to changes in their properties compared to those of the initial components, and the distortions of the polyhedra may improve the spectroscopic properties of activators involved in these solid solutions.