Charge transfer-type fluorescence of Ti-doped Ca14Al10Zn6O35

The calcium aluminum zincates Ca14(Al1-2xTixZnx)10Zn6O35, in which Al3+ sites in the host material Ca14Al10Zn6O35 are simultaneously substituted by Ti4+ and Zn2+, were synthesized by a polymerized complex method. Al3+ ions could be replaced up to an x value of 0.1. The host material does not exhibit fluorescence, while the cation-substituted samples show an emission band centered at 383 nm under excitation by UV light at 243 nm. The emission intensity increases with x up to 0.1 and then gradually decreases as x is further increased. The emission wavelength also becomes longer with increasing temperature. Based on the properties of other Ti4+-containing fluorescent materials, the emission of Ca14(Al1-2xTixZnx)10Zn6O35 is attributed to charge transfer-type fluorescence resulting from [TiO6] octahedra.