Growth, characterization and vibrational spectroscopy of (NH4)2NixMn(1−x)(SO4)2.6H2O:Nd crystals

Abstract

In this work, mixed crystals of the Tutton’s salt family with empirical formula (NH4)2NixMn(1−x)(SO4)2.6H2O were synthesized with partial occupation of Ni, Mn and doped with Nd, in different stoichiometric fractions employing slow evaporation of the solvent technique. The crystal decomposition processes were analyzed with the help of thermogravimetric analysis system coupled to an FT-IR spectrometer. Dehydration gases H2O and other gases, such as SO3 and NH3 resulting from the degradation of SO4 and NH4 molecules, have been identified, whose presence in the crystalline structure was confirmed by Raman spectroscopy and FT-MIR in the ATR mode. Normal vibrational modes of the octahedral complexes of [X(H2O)6] and residual oxides resulting from TG analysis, were also investigated with the help of Raman spectroscopy. X-ray powder diffraction revealed the crystallinity of the samples. The presence of Ni and Mn were confirmed employing EDS spectroscopy and the quantification of Ni, Mn and Nd in the crystal was determined using ICP-MS technique.