The defect structure and diffusional processes have been studied in the anion-excess fluorite (Sr, Y)Cl2.03 by diffuse neutron scattering techniques. Static cuboctahedral clusters found at ambient temperature break up at temperatures below 1050 K, where the anion disorder is highly dynamic. The anion diffusion rate is faster than that for pure SrCl2 at the same temperature.
Goff, J. P., Clausen, K. N., Fåk, B., Godfrin, H., Hadfield, R., Hayes, W., Hull, S., & Hutchings, M. T. (1992). Diffuse neutron scattering from anion-excess strontium chloride. Physica B: Condensed Matter, 180/181, 819-821. https://doi.org/10.1016/0921-4526(92)90479-C