The microstructural and luminescence characteristics ofsolid state (SS) and sol-gel (SG) processed CaTiO3:Pr3+powders have been investigated as a function of the grinding time t, in the caseof SSt samples and of OH/Ti(OPr)4 molar ratios r, in the case of SGrsamples. It is observed that either extended post-synthesis grinding or sol-gelsyntheses operated under acid or neutral conditions lead to submicron grainedmicrostructures, CaTiO3 + TiO2 phase mixing and finally toless efficient phosphors. The observed decrease of luminescence intensity iscorrelated to the presence of non-luminescent rutile and to the amount ofsubmicron particles.
