Preparation and characterisation of ammonium lanthanide double sulphate monohydrates

Abstract The ammonium lanthanide double sulphate monohydrates NH 4 Ln(SO 4 ) 2 ·H 2 O (Ln = Eu-Yb and Y) were synthesised and characterised by chemical, thermal, infrared and X-ray powder diffraction methods. The heats of dehydration were calculated from measurements of the peak areas under the differential thermal analysis curve recorded during thermal dehydration of the compounds. The infrared spectra coupled with X-ray data showed that these compounds are structurally isomorphous to RbLn(SO 4 ) 2 ·H 2 O reported in the literature, and that the lanthanide metal ion is coordinated to eight oxygen atoms.