Rare earth carbonate borate boron rare earth - carbonate or carbonate of itrio boron boron of itrio gadolinium processes for the preparation of a carbonate boron.Of the earth - rare and rare earth bor

摘要

The present invention relates to a rare earth borate, a precursor thereof, their preparation processes and the use of such borate as luminophore. The rare earth borate and its precursor are characterized in that they are provided in the form of cubic, parallelepipedic or spherical particles and in that they have a dispersion index of at least 0.8. According to one embodiment of the invention, the borate is a red luminophore. The process of preparing the precursor is characterized in that a rare earth hydroxycarbonate or carbonate is reacted with boric acid, the reaction medium being an aqueous solution. The borate is obtained by calcining the precursor.