Autor(es)

Ferrari, Jefferson L. ^[1] ; Lima, Karmel O. ^[1] ; Maia, Lauro J. Q. ^[2] ; Ribeiro, Sidney J. L. ^[3] ; Goncalves, Rogeria R. ^[1]

Afiliação do(s) autor(es)

^[1] USP, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Goias, Grp Fis Mat, Inst Fis, BR-74001970 Goiania, Go - Brazil

^[3] UNESP, Lab Mat Foton, Inst Quim, BR-14801970 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the American Ceramic Society; v. 94, n. 4, p. 1230-1237, APR 2011.
• Citações Web of Science: 27

Resumo

This paper reports on the preparation and structural, morphological, and luminescence properties of Er3+-doped nanocomposites based on SiO(2)-Ta(2)O(5) prepared by the sol-gel method. The influence of the tantalum oxide content on the structural and spectroscopic properties was analyzed for Si/Ta molar ratios of 90:10, 80:20, 70:30, 60:40, and 50:50. The sols were kept at 60 degrees C for formation of the xerogel, followed by annealing at 900 degrees, 1000 degrees, and 1100 degrees C for 2 h for production of the nanocomposites. The densification, phase separation, and crystallization processes were monitored through vibrational spectroscopy (FTIR), X-ray diffraction, and high-resolution transmission electron microscopy. Er3+ emission in the infrared region, assigned to the 4I(13/2)-> 4I(15/2) transition, was observed for all the nanocomposites. Evolution from a vitreous-like environment to a crystalline one was identified upon increasing the annealing temperature and tantalum content. According to the results obtained, the Er3+ ions are preferentially localized close to the region rich in Ta(2)O(5) nanoparticles. The localization of Er3+ ions was shown to be dependent on the amount of tantalum. Moreover, the fact that the Er3+ ions are located close to Ta(2)O(5) nanoparticles promotes a broadband emission with full-width at half-maximum of 90 nm around 1550 nm. (AU)