Vibrational Characteristics of New Double Tungstates Li2MII(WO4)2 (M = Co, Ni and Cu)
M. Maczka; J. Hanuza; U. Amador; A.F. Fuentes. Vibrational Characteristics of New Double Tungstates Li2MII(WO4)2 (M = Co, Ni and Cu). Journal of Raman Spectroscopy (ISSN: 0377-0486). 2002, Vol. 33, p. 56-2002.
For the first time, Raman and IR studies were performed on new double tungstates Li2MII(WO4)2 (M = Co, Ni and Cu) crystallizing in the wolframite-type structure. The observed vibrational modes were assigned to the respective motions of atoms in the unit cell. The vibrational properties of the Cu derivative differ significantly from those of the cobalt and nickel derivatives. The differences were attributed to the differences in the crystal structures. A comparison of the results with literature data for MIIWO4 and LiMIII(WO4)2 (MII = Zn, Fe, Cu; MIII = Fe, In, Sc), crystallizing in the wolframite-like structure, revealed a very large splitting for a few bridging modes and large shifts of the low-wavenumber modes towards higher wavenumbers in the case of Li2MII(WO4)2. These features were assigned to different arrangements of tungsten–oxygen interactions within the infinite chains, which results in the formation of two nonequivalent oxygen bridges in the structure of the compounds studied
For the first time, Raman and IR studies were performed on new double tungstates Li2MII(WO4)2 (M = Co, Ni and Cu) crystallizing in the wolframite-type structure. The observed vibrational modes were assigned to the respective motions of atoms in the unit cell. The vibrational properties of the Cu derivative differ significantly from those of the cobalt and nickel derivatives. The differences were attributed to the differences in the crystal structures. A comparison of the results with literature data for MIIWO4 and LiMIII(WO4)2 (MII = Zn, Fe, Cu; MIII = Fe, In, Sc), crystallizing in the wolframite-like structure, revealed a very large splitting for a few bridging modes and large shifts of the low-wavenumber modes towards higher wavenumbers in the case of Li2MII(WO4)2. These features were assigned to different arrangements of tungsten–oxygen interactions within the infinite chains, which results in the formation of two nonequivalent oxygen bridges in the structure of the compounds studied