13 research outputs found
Raman and FTIR Spectroscopic Studies of Potassium Titanyl Phosphate (KTiOPO4) Doped with Lanthanum and Praseodymium
Vibrational spectroscopic studies of Guanidinium metal (MII) sulphate hexahydrates [MII = Co, Fe, Ni]
The Raman and FTIR spectra of [C(NH2)3]2M(SO4)2 ·6H2O (withM= Co, Fe, Ni) were recorded and analysed. The observed spectral bands
are assigned in terms of vibrations of guanidinium ions, sulphate groups and water molecules. The analysis shows that the sulphate tetrahedra
are distorted from their free state symmetry Td to C1. This is attributed to the presence of hydrogen bonds from water molecules. The order of
distortion of the metal oxygen octahedra influenced the distortion of the sulphate tetrahedra. The appearance of 1– 3 modes of water molecules
above 3300 cm−1 indicates the presence of weak hydrogen bondsCochin University of Science and TechnologySolid State Communications 143 (2007) 348–35
Raman and FTIR studies of the structural aspects of Nasicon-type crystals; AFeTi(PO4)3 [A ¼ Ca, Cd]
Raman and FTIR spectra of CaFeTi(PO4)3 and CdFeTi(PO4)3 are recorded and analyzed. The observed bands are assigned in terms
of vibrations of TiO6 octahedra and PO4 tetrahedra. The symmetry of TiO6 octrahedra and PO4 tetrahedra is lowered from their free ion
symmetry. The presence of Fe3+ ion disrupts the Ti–O–P–O–Ti chain and leads to the distortion of TiO6 octrahedra and PO4 tetrahedra.
The PO4 3 tetrahedra in both crystals are linearly distorted. The covalency bonding factor of PO4 3 polyanion of both the crystals are
calculated from the Raman spectra and compared to that of other Nasicon-type systems. The numerical values of covalency bonding
factor indicates that there is a reduction in redox energy and cell voltage and is attributed to strong covalency of PO4 3 polyanioninJournal of Physics and Chemistry of Solids 69 (2008) 1985–198
Raman and Ftir Spectral Investigations of Twinned M(IO3)2 (M = Mn, Ni, Co, AND Zn) Crystals
International audienc
Formation of carbon-encapsulated metallic nano-particles from metal acetylides by electron beam irradiation
Transition metal acetylides, MC2 (M=Fe, Co and Ni), exhibit ferromagnetic behavior of which
TC is characteristic of their size and structure. CoC2 synthesized in anhydrous condition exhibited cubic
structure with disordered C2− 2 orientation. Once being exposed to water (or air), the particles behave
ferromagnetically due to the lengthening of the Co–Co distance by the coordination of water molecules to
Co2+ cations. Heating of these particles induces segregation of metallic cores with carbon mantles. Electron
beam or 193 nm laser beam can produce nanoparticles with metallic cores covered with carbon mantlesEur. Phys. J. D 34, 219–222 (2005
Raman and Ftir Spectral Investigations of Twinned M(IO3)2 (M = Mn, Ni, Co, AND Zn) Crystals
Spray pyrolytic deposition of ZnO thin layers composed of low dimensional nanostructures
FT-IR and FT-Raman study of Nasicon type phosphates, ASnFe(PO4)3 [A=Na2, Ca, Cd]
FT-Raman and FT-IR spectra of ASnFe(PO4)3 [A=Na2, Ca, Cd] were recorded and analyzed. The bands
were assigned in terms of the vibrational group frequencies of SnO6 octahedral and PO4 tetrahedral. The
spectral analysis shows that the symmetry of corner shared octahedral (SnO6) and the tetrahedral (PO4)
are lowered from their free ion symmetry state. The presence of Fe3+ ions disrupts the S–N–O–S–N chain
in the structure. This causes distortion of SnO6 and PO4 in the structure of all the compounds. Also it is
seen that there are two distinct PO4 tetrahedra of different P–O bond lengths. One of these tetrahedra
is linearly distorted in all the title compounds. The PO4 frequencies and bond lengths are calculated
theoretically and are in agreement with the experimental values. The presence of PO4 polyanion in the
structure can reduce the redox energy and hence reduce the metal oxygen covalency strength in the
structureCochin University of Science and TechnologySpectrochimica Acta Part A 78 (2011) 415–41