Characterisation of YAG:Ce powders thermal treated at different temperatures

Submicronic, spherical, polycrystalline YAG:Ce powders with luminescence properties were synthesised through aerosol processing route from the corresponding nitrates solution. Additional heat treatment was performed in the temperature range from 1000 to 1200 8C in order to increase the crystallinity of the obtained cubic garnet phase. SEM examination and subsequent morphological analysis allowed studying the surface properties and particle size distributions. An Image Processor was used to measure particle surface roughness. Quantitative SEM/EDS analysis indicated the synthesised materials present high purity and compositional homogeneity. TEM and selected area electron diffraction (SAED) showed a high crystallinity of the samples. XRD patterns of the powders were recorded in the region of 2y ¼ 108–808. The evolution of crystallite size was performed measuring of the broadening of a particular peak using the Scherrer equation. It was found that the crystallite size and bulk particles size vary with the applied temperature. The observed changes in function of the different thermal treatments were correlated with the photoluminescence (PL) properties of these materials.