Raman characterisation of powder of cubic RE2O3 (RE = Nd, Gd, Dy, Tm, and Lu), Sc2O3 and Y2O3

Abstract Raman spectra of cubic Sc 2 O 3 , Y 2 O 3 and C-type rare earth oxides are presented. Cubic Nd 2 O 3 is prepared by thermal decomposition of its hydroxide. The decomposition mechanism happens in two steps. At the end of this process cubic Nd 2 O 3 form. All Raman spectra are characterised by the presence of a very strong band in the range 320–420 cm −1 , depending on the lattice parameter of each oxide. Frequency of this line decreases increasing the cell constant, meaning that the structure becomes less rigid. A simply approach is used in order to give a consistent evaluation of the force constant of each oxide. The position of the low wave number bands depends mainly on the cationic mass, meaning that these bands are not due to stretching vibrations, but rather to bending vibrations.

[1]  M. Zhang,et al.  Grain size effects in Bi4Ti3O12 nanocrystals investigated by Raman spectroscopy , 2004 .

[2]  D. Bloor,et al.  Spectroscopy of rare earth oxide systems. I. Far infrared spectra of the rare earth sesquioxides, cerium dioxide and nonstoichiometric praseodymium and terbium oxides , 1972 .

[3]  Renata Reisfeld,et al.  Lasers and Excited States of Rare Earths , 1977 .

[4]  W. White,et al.  Vibrational spectra of oxides with the C-type rare earth oxide structure , 1972 .

[5]  G. Schaack,et al.  Phonon and Electronic Raman Spectra of Cubic Rare-Earth Oxides and Isomorphous Yttrium Oxide* , 1970 .

[6]  B. Davis.  Dehydration and dehydrogenation of 2-octanol by thorium oxide , 1972 .

[7]  J. Kašpar,et al.  Laser-Excited Luminescence of Trivalent Lanthanide Impurities and Local Structure in CeO2−ZrO2 Mixed Oxides , 2004 .

[8]  T. Masui,et al.  Preparation of the cubic-type La2O3 phase by thermal decomposition of LaI3 , 2005 .

[9]  Nobuhito Imanaka,et al.  The Binary Rare Earth Oxides. , 1998 .

[10]  T. D. Chikalla,et al.  Polymorphic Modifications of Pm2O3 , 1972 .

[11]  M. Lastusaari,et al.  Crystal field strength in C-type cubic rare earth oxides , 2002 .

[12]  M. Kis-Varga,et al.  X-ray diffraction and Raman scattering in SbSI nanocrystals , 2003 .

[13]  M. Yoshimura,et al.  Characterization by Raman spectroscopy of solid solutions in the yttria-rich side of the zirconia–yttria system , 2002 .

[14]  C. Goutaudier,et al.  Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic and monoclinic Gd2O3 ☆ , 2001 .

[15]  R. Hempelmann,et al.  Gradients in structure and dynamics of Y2O3 nanoparticles as revealed by X-ray and Raman scattering , 2001 .

[16]  Toshio Suzuki,et al.  RAMAN SCATTERING AND LATTICE DEFECTS IN NANOCRYSTALLINE CEO2 THIN FILMS , 2002 .

[17]  A. Dedov,et al.  Oxidative coupling of methane catalyzed by rare earth oxides: Unexpected synergistic effect of the oxide mixtures , 2003 .

[18]  Burns,et al.  Anomalous Raman spectra from La2CuO4. , 1990, Physical review. B, Condensed matter.

[19]  G. Zou,et al.  Grain size effect on ferroelectric phase transition in Pb1 − xBaxTiO3 ceramics , 1998 .

[20]  S. I. Boldish,et al.  Vibrational spectra of crystals with the A-type rare earth oxide structure—I. La2O3 and Nd2O3 , 1979 .

[21]  D. Wiechert,et al.  VUV spectroscopy of luminescent materials for plasma display panels and Xe discharge lamps , 2001 .

[22]  Sanda Rončević,et al.  Non-vibrational features in NIR FT-Raman spectra of lanthanide sesquioxides , 2004 .

[23]  G. Hussein.  Rare earth metal oxides: formation, characterization and catalytic activity Thermoanalytical and applied pyrolysis review , 1996 .

[24]  C. Proust,et al.  Vibrational Spectroscopy of the C-Form of Yttrium Sesquioxide , 1995 .

[25]  L. Sangaletti,et al.  Growth and microstructural analysis of nanosized Y2O3 doped with rare earths , 2000 .

[26]  J. Panitz,et al.  A Raman spectroscopic study of rare earth mixed oxides , 2000 .

[27]  S. Lin,et al.  Raman and Resonance Raman Spectroscopy of Selected Rare-Earth Sesquioxides , 1984 .

[28]  J. Mackenzie,et al.  Superconducting YBa 2 Cu 3 O 7− x fibers from the thermoplastic gel method , 1989 .

[29]  B. Viana,et al.  Optical crystal field study of Sm2O3 (C- and B-type) , 1998 .

[30]  R. Portier,et al.  Mise en evidence par microscopie electronique de marches a la surface de cristaux minces de sesquioxydes de terres rares , 1973 .

[31]  M. Urban,et al.  Bonding anomalies in the rare earth sesquioxides , 1987 .

[32]  A. Abrão,et al.  Sequential separation of the yttrium-heavy rare earths by fractional hydroxide precipitation , 2004 .