Synthesis, Thermal Analysis, Spectroscopic Properties, and Degradation Process of Tutton Salts Doped with AgNO 3 or H 3 BO 3 .

In this work, we synthesized and studied the spectroscopic properties of (NH 4 ) 2 (SO 4 ) 2 Y(H 2 O) 6 (Y = Ni, Mg) crystals doped with AgNO 3 or H 3 BO 3 . These crystals constitute a series of hexahydrated salts known as Tutton salts. We investigated the influence of dopants on the vibrational modes of the tetrahedral ligands NH 4 and SO 4 , octahedral complexes Mg(H 2 O) 6 and Ni(H 2 O) 6 , and H 2 O molecules present in these crystals through Raman and infrared spectroscopies. We were able to identify bands that are attributed to the presence of Ag and B dopants, as well as band shifts caused by the presence of these dopants in the crystal lattice. A detailed study of the crystal degradation processes was performed by thermogravimetric measurements, where there was an increase in the initial temperature of crystal degradation due to the presence of dopants in the crystal lattice. Raman spectroscopy of the crystal residues after the thermogravimetric measurements helped us to elucidate the degradation processes occurring after the crystal pyrolysis process.