Abstract: The invention relates to a process for preparing suspensions of nanoparticulate solids, wherein the solids present in the suspension are present in the form of nanoparticulate primary particles or very small aggregates.

Abstract: The present invention relates to a process for preparing essentially isometric nanoparticulate lanthanide-boron compounds or solid mixtures comprising essentially isometric nanoparticulate lanthanide-boron compounds, which comprises a) mixing i) one or more lanthanide compounds selected from the group consisting of lanthanide hydroxides, lanthanide hydrides, lanthanide chalcogenides, lanthanide halides, lanthanide borates and mixed compounds of the lanthanide compounds mentioned, ii) one or more compounds selected from the group consisting of crystalline boron, amorphous boron, boron carbides, boron hydrides and boron halides and iii) if appropriate one or more reducing agents selected from the group consisting of hydrogen, carbon, organic compounds, alkaline earth metals and alkaline earth metal hydrides dispersed in an inlet carrier gas with one another, b) reacting the mixture of the components i), ii) and, if appropriate, iii) in the inert solvent by means of thermal treatment within a reaction zone,