UV-excited piezo-optical effects in oxide nanocrystals incorporated into PMMA matrices

Measurements of UV-laser stimulated piezo-optical effects were conducted on nanocrystals (NC) of several double tungstate materials such as Ln3+:KYb(WO4)2 (Ln = Eu and Er) and KGd(WO4)2 immersed in poly(methyl methacrylate) (PMMA) matrices. At the same time, similar measurements were performed on KNd(PO3)4 and KTiOPO4 NC for comparison. The NC were synthesized by a modified Pechini method with maximum calcination temperatures of 973–1173 K. It was established that the incorporation of NC with a large dispersion of sizes and substantial aggregation favors UV-induced piezo-optical effects which are dependent only on the content of the NC being optimal at 10–12% in weighting units. The measured piezo-optical dependences are related to the chemical content of the compounds that form the NC studied.