Sol-gel route has been successfully used to obtain pure Y_3Al_5O_(12) and Y_3Al_5O_(12)Eu~(3+) powders and films. Advanced YAG coatings were achieved by two techniques, the spray and dip-coating methods, giving rise to different characteristics and properties. The materials structure and microstructure were analyzed by means of X-ray diffraction and scanning electron microscopy. It has been shown that sol-gel processed YAG powders crystallize around 900℃ whereas a temperature much higher is necessary to obtain this compound by solid state synthesis (≈1500℃). Additionally the surface of the films was observed by atomic force microscopy. Eventually, laser induced luminescence spectra, as well as luminescence decays of Eu~(3+) ions show undoubtedly the spectral features of a Eu~(3+) emitting centre embedded in a unique site of D_2 symmetry.
展开▼
