%0 Journal Article %1 WOS:000276665500056 %A Valente, M A %A Silva, C C %A Sombra, A S B %A Graca, M P F %C PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS %D 2010 %I ELSEVIER SCIENCE BV %J JOURNAL OF NON-CRYSTALLINE SOLIDS %K (xerogels); Conductivity; Dielectric Electric Relaxation; Scanning Silicates; Sol-Gels X-ray ceramics; diffraction; diffraction} electron microscopy; modulus; properties; {Glass %N 11-17 %P 800-804 %R 10.1016/j.jnoncrysol.2009.09.044 %T Dielectric spectroscopy of LiNbO3 and TmNbO4 nanocrystals embedded in a SiO2 glass matrix %V 356 %X In this paper we present the preparation, by the sol-gel method, of a transparent SiO2:Li2O:Nb2O5 glass doped with Tm3+. The dried gel was heat-treated (HT), in air, at temperatures between 500 and 800 degrees C. The obtained glasses and glass-ceramics were studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), dc conductivity (sigma(dc)), ac conductivity (sigma(ac)) and by dielectric measurements. The X-ray diffraction patterns show that SiO2 and LiNbO3 crystal phases are present in the samples treated at temperatures above 650 degrees C. Besides the SiO2 and LiNbO3, TmNbO4 crystal phase was detected in the samples treated above 750 degrees C. The XRD and SEM show that the average particles size and number increases with the rise of the HT temperature. The electrical and dielectrical properties were related with the glass and glass-ceramics microstructure. (C) 2010 Elsevier B.V. All rights reserved.

@article{WOS:000276665500056, abstract = {In this paper we present the preparation, by the sol-gel method, of a transparent SiO2:Li2O:Nb2O5 glass doped with Tm3+. The dried gel was heat-treated (HT), in air, at temperatures between 500 and 800 degrees C. The obtained glasses and glass-ceramics were studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), dc conductivity (sigma(dc)), ac conductivity (sigma(ac)) and by dielectric measurements. The X-ray diffraction patterns show that SiO2 and LiNbO3 crystal phases are present in the samples treated at temperatures above 650 degrees C. Besides the SiO2 and LiNbO3, TmNbO4 crystal phase was detected in the samples treated above 750 degrees C. The XRD and SEM show that the average particles size and number increases with the rise of the HT temperature. The electrical and dielectrical properties were related with the glass and glass-ceramics microstructure. (C) 2010 Elsevier B.V. All rights reserved.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, author = {Valente, M A and Silva, C C and Sombra, A S B and Graca, M P F}, biburl = {https://www.bibsonomy.org/bibtex/230ec66a9e0b254e1ca6d724d1b1cb222/ppgfis_ufc_br}, doi = {10.1016/j.jnoncrysol.2009.09.044}, interhash = {1e6b6732cb0b21a27887f5f41232d372}, intrahash = {30ec66a9e0b254e1ca6d724d1b1cb222}, issn = {0022-3093}, journal = {JOURNAL OF NON-CRYSTALLINE SOLIDS}, keywords = {(xerogels); Conductivity; Dielectric Electric Relaxation; Scanning Silicates; Sol-Gels X-ray ceramics; diffraction; diffraction} electron microscopy; modulus; properties; {Glass}, note = {5th International Conference on Dielectric Spectroscopy and Its Applications, Lyon, FRANCE, AUG 26-29, 2008}, number = {11-17}, pages = {800-804}, publisher = {ELSEVIER SCIENCE BV}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Dielectric spectroscopy of LiNbO3 and TmNbO4 nanocrystals embedded in a SiO2 glass matrix}, tppubtype = {article}, volume = 356, year = 2010 }