Lanthanide ions react with vanadium(V)-oxide xerogels forming intercalation compounds. In contrast to the pure vanadium(V)-oxide matrix, the removal of the water molecules from the interlamellar space and from the lanthanide coordination shell is practically complete at 150 degrees C, disrupting the bidimensional layered structure. The heating above 450 degrees C leads to the formation of orthorhombic V2O5 and tetragonal lanthanide orthovanadates.