%0 Journal Article
%T Photoluminescence behavior of the Sm3+ and Tb3+ ions doped into the Gd2(WO4)3 matrix prepared by the Pechini and ceramic methods
%A Kodaira
%A Cl¨¢udia A.
%A Brito
%A Hermi F.
%A Teotonio
%A Ercules E. S.
%A Felinto
%A Maria Cl¨¢udia F. C.
%A Malta
%A Oscar L.
%A Brito
%A Giancarlo E. S.
%J Journal of the Brazilian Chemical Society
%D 2004
%I Sociedade Brasileira de Qu¨ªmica, SBQ
%R 10.1590/S0103-50532004000600016
%X the gd2(wo4)3:re3+ compounds (where re3+ = sm and tb) were prepared by the pechini and ceramic methods and characterized by x-ray diffraction and infrared spectroscopy. these rare earth materials present high orange (sm3+-compound) and green (tb3+-compound) luminescence intensity under uv radiation. the excitation spectra of these compounds presented broad bands arising from ligand-to-metal charge transfer (o£¿w and o£¿re3+) and narrow bands from 4f-intraconfigurational transitions. the excitation spectra of tb3+ system also exhibit broad bands attributed to the interconfigurational transition (4f-5d). the emission spectra exhibited the 4g5/2£¿6hj (j = 5/2, 7/2, 9/2 and 11/2) and 5d4£¿ 7fj (j = 0-6) transitions (direct excitation), for the systems doped with sm3+ and tb3+, respectively, while a broad band assigned to the lmct (o£¿w) is observed when the excitation is monitored on the o£¿w lmct state around 270 nm. the experimental intensity parameters hsm and heu present similar behaviors, suggesting that the sm3+ ion is in a highly polarizable chemical environment with similar covalent character of the metal-donor atom interaction to the tungstate doped europium system. the cross-relaxation process from the 5d3 to the 5d4 levels of the gd2(wo4)3:tb3+ system has been also reported.
%K samarium
%K terbium
%K pechini and ceramic methods
%K tungstate
%K photoluminescence.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0103-50532004000600016&lng=en&nrm=iso&tlng=en