Structure and Water-resistance of Rare-earth Luminescent Materials Coated with Si and Al

The rare-earth luminescent materials coated with Si and Al were prepared by the sol-gel route. The result of FL measurement indicates that the coated sample has the similar luminescent properties to that of the uncoated. The compositions, microstructure, texture and surface morphology of the binary films containing Si and Al elements were investigated by SEM,XRD,BET and XPS. Water-resistance of the coated and uncoated samples was evaluated by measuring the pH of water in which the samples were dispersed. The results show that a thin dense binary film containing Si and Al elements forms on the surface of the sample through chemical interactions, which can enhance the uncoated sample's stability under water-containing conditions.