Oxide coatings on Y3Al5O12:Tb3+ particles

A coating method with precipitating process was developed to reduce the particle size and to improve the particle dispersion of Y3Al5O12:Tb3+ phosphor prepared by sol-gel method. The particle morphology was observed by using SEM and TEM; and the particle size and its dispersion was measured by using laser scattering technique. Several coating materials were tested. Among them, Al2(SiO3)3 coating not only reduced the particle size from several micrometers to ∼1 μm and improved the particle dispersion, but also well kept luminescent intensities and improved the duration of the phosphor under the bombardment of cathode ray. The mechanism of the particle size reduction was proposed.