Synthesis and characterization of rare earth phosphates with luminescent properties using precursors containing tripolyphosphates by spray-drying process

Abstract

Luminescent materials, also known as "phosphors", nowadays receive great attention due to its diverse applications and great commercial importance. The study of the attainment processes aiming at the applications of such compounds is, therefore, a stimulant theme in the Materials Science and in Inorganic Chemistry. Among these phosphors, are distinguished the compounds containing Rare Earth, elements with atomic number between 57 (Lanthanum ) and 71 (Lutetium), besides Scandium (Z=21) and Yttrium (Z=39). Great part of the Rare Earth ions, mainly in the oxidation state +3, possesss unique luminescent properties, those confers to them the possibility of formation of compounds with vast applications. Due to its great stability and high luminescence efficiencies, the phosphates are found between the main compounds containing Rare Earth. This work, that intends to explore the luminescence of these materials, aims at search new (or more viable) synthetic routes for Rare Earth phosphate using tripolyphosphate ion (P3O105 -) as complexing agent and as precursor of ortophosphate ions (PO43 -) in a spray-drying process (technique of evaporation of solvents). Due to its peculiar properties, joined to adequate conditions of drying, the tripolyphosphate anion tends to make possible a manipulation in nanometric scale in such materials. This manipulation has as objective to reach size and surface properties of particles, both basic ones for good yields in the luminsecence phenomenon.