Raman spectroscopy study of layered-double hydroxides containing magnesium and trivalent metals

Abstract We examined the Raman spectra for LDHs containing Mg 2+ and a trivalent metal (Al 3+ , Ga + or In + ) with an Mg 2+ /M 3+ ratio of 3. The Raman spectra exhibited very strong signals at ca . 1060 cm –1 , 540 cm –1 and 150 cm –1 that were ascribed to symmetric stretching of interlayer carbonate ions, symmetric stretching of Mg–O–Mg bonds in Mg 3 (OH) structural units and stretching of M–O bonds, respectively. The spectra additionally contained various weaker signals suggesting that the LDHs studied consist solely of Mg 3 (OH) and Mg(OH) 2 M(III)O structural units.