Production of phosphor (YAG∶Tb) fine particles by hydrothermal synthesis in supercritical water

Rapid and continuous production of phosphor (YAG∶Tb) fine particles by hydrothermal synthesis in supercritical water was studied. At temperatures higher than the critical temperature of water, continuous and rapid (<60 s) production of YAG∶Tb fine particles was achieved. Emission spectra obtained by UV excitation of the particles were in agreement with the typical spectral pattern of YAG∶Tb. Single phase YAG∶Tb was produced by using stoichiometric mixtures of metal salts [Al(NO 3 ) 3 , Y(NO 3 ) 3 , and TbCl 3 ] as aqueous solutions with an alkali molar ratio {[OH – ]/([NO 3 – ] + [Cl – ])} of 1 and a rapid heating method. No additional thermal treatment was necessary to obtain crystalline products.