Composition Based On a Samarium Sesquisulphide Process of Preparation and Use as Colouring Pigment

摘要

The present invention is based on samarium selenide sulfide, and has a samarium purity of at least 99% with respect to other rare earth metals, comprising at least one alkali metal or alkaline earth metal element, at least the alkali metal or alkaline earth metal element And a part thereof is contained in the crystal lattice of the sesquioxide sulfide. In another embodiment, the composition is based on a sesquium and a sesquiozide of at least one rare earth metal that is only trivalent, and comprises at least one alkali metal or alkaline earth metal element, wherein at least a portion of the alkali metal or alkaline earth metal element And is contained in the crystal lattice of the sesquioxide sulfide. In a third embodiment, the samarium purity of the composition is such that the cerium content is 1% or less. The method of making these compositions consists of reacting a compound of samarium, trivalent rare earth metals, and an alkali metal or alkaline earth metal with a gaseous mixture of hydrogen sulfide and carbon disulfide.