skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Crystallization and spectroscopic properties investigations of Er{sup 3+} doped transparent glass ceramics containing CaF{sub 2}

Abstract

Transparent oxyfluoride glass ceramics with composition of 45SiO{sub 2}-25Al{sub 2}O{sub 3}-5CaCO{sub 3}-10NaF-15CaF{sub 2}-0.5ErF{sub 3} (in mol%) were developed through controlled crystallization of melt-quenched glass. Non-isothermal crystallization kinetics investigation showed that the average apparent activation energy E {sub a} and Avrami exponent n are about 283 kJ/mol and 2.22, respectively, indicating the crystallization a three dimensional crystal growth process controlled by the diffusion with a decreasing nucleation rate. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) observation revealed the precipitation of CaF{sub 2} crystallites sized about 15 nm among the glass matrix after heat-treatment at 650 deg. C for 2 h. For as-made glass, no upconversion signals were detected when excited with a 30 mW diode laser at 980 nm, while strong upconversion emissions at 545, 660 and 800 nm were obtained for transparent glass ceramic under similar excitation conditio000.

Authors:
 [1];  [2];  [1];  [1];  [1];  [1]
  1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Yangqiao West Road 155, Fuzhou 350002 (China)
  2. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Yangqiao West Road 155, Fuzhou 350002 (China). E-mail: yswang@fjirsm.ac.cn
Publication Date:
OSTI Identifier:
20891611
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 41; Journal Issue: 1; Other Information: DOI: 10.1016/j.materresbull.2005.07.016; PII: S0025-5408(05)00272-2; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AFTER-HEAT; CALCIUM FLUORIDES; CERAMICS; DOPED MATERIALS; ERBIUM IONS; EXCITATION; GLASS; LASERS; MICROSTRUCTURE; OPTICAL PROPERTIES; PRECIPITATION; TRANSMISSION ELECTRON MICROSCOPY

Citation Formats

Hu Zhongjian, Wang Yuansheng, Ma En, Bao Feng, Yu Yunlong, and Chen Daqin. Crystallization and spectroscopic properties investigations of Er{sup 3+} doped transparent glass ceramics containing CaF{sub 2}. United States: N. p., 2006. Web.
Hu Zhongjian, Wang Yuansheng, Ma En, Bao Feng, Yu Yunlong, & Chen Daqin. Crystallization and spectroscopic properties investigations of Er{sup 3+} doped transparent glass ceramics containing CaF{sub 2}. United States.
Hu Zhongjian, Wang Yuansheng, Ma En, Bao Feng, Yu Yunlong, and Chen Daqin. Thu . "Crystallization and spectroscopic properties investigations of Er{sup 3+} doped transparent glass ceramics containing CaF{sub 2}". United States. doi:.
@article{osti_20891611,
title = {Crystallization and spectroscopic properties investigations of Er{sup 3+} doped transparent glass ceramics containing CaF{sub 2}},
author = {Hu Zhongjian and Wang Yuansheng and Ma En and Bao Feng and Yu Yunlong and Chen Daqin},
abstractNote = {Transparent oxyfluoride glass ceramics with composition of 45SiO{sub 2}-25Al{sub 2}O{sub 3}-5CaCO{sub 3}-10NaF-15CaF{sub 2}-0.5ErF{sub 3} (in mol%) were developed through controlled crystallization of melt-quenched glass. Non-isothermal crystallization kinetics investigation showed that the average apparent activation energy E {sub a} and Avrami exponent n are about 283 kJ/mol and 2.22, respectively, indicating the crystallization a three dimensional crystal growth process controlled by the diffusion with a decreasing nucleation rate. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) observation revealed the precipitation of CaF{sub 2} crystallites sized about 15 nm among the glass matrix after heat-treatment at 650 deg. C for 2 h. For as-made glass, no upconversion signals were detected when excited with a 30 mW diode laser at 980 nm, while strong upconversion emissions at 545, 660 and 800 nm were obtained for transparent glass ceramic under similar excitation conditio000.},
doi = {},
journal = {Materials Research Bulletin},
number = 1,
volume = 41,
place = {United States},
year = {Thu Jan 05 00:00:00 EST 2006},
month = {Thu Jan 05 00:00:00 EST 2006}
}
  • Transparent Tb{sup 3+} and Yb{sup 3+} codoped oxyfluoride glass ceramics containing CaF{sub 2} nanocrystals were prepared by melt quenching and subsequent heat treatment. Crystallization kinetics of CaF{sub 2} nanocrystals was investigated by differential scanning calorimetric method. The average apparent activation energy E{sub a} of the crystallization was {approx}498 kJ/mol. Moreover, the value of the Avrami exponent n was 1.01. These results suggest that the crystallization mechanism of CaF{sub 2} is a diffusion controlled growth process of needles and plates of finite long dimensions. X-ray diffraction patterns and transmission electron microscopy image confirmed the CaF{sub 2} nanocrystals in the glass ceramic.more » Ultraviolet (UV) and visible emission spectra of the as-made glass and the glass ceramic with an excitation of a 974 nm laser diode were recorded at room temperature. An intense UV emission at 381 nm was observed in the glass ceramic. The origin of the enhancement of the emission at 381 nm was investigated using spectroscopic technique and Judd-Ofelt analysis. The enhancement of the emission at 381 nm could be attributed to the change of the ligand field of Tb{sup 3+} ions due to the incorporation of some Tb{sup 3+} and Yb{sup 3+} ions into CaF{sub 2} nanocrystals in the glass ceramic.« less
  • The Er{sup 3+} doped transparent oxyfluoride glass ceramics containing Sr{sub 2}GdF{sub 7} nanocrystals were prepared and their spectroscopic properties were discussed. The formation of Sr{sub 2}GdF{sub 7} nanocrystals in the glass ceramics was confirmed by x-ray diffraction. The split peaks of the upconversion and near infrared emission bands of the Er{sup 3+} doped glass ceramics can be observed. The upconversion luminescence intensity of Er{sup 3+} in the glass ceramics increased significantly with the increasing heat treated temperature. The luminescence decay curves and time-resolved spectra indicated that the lifetime of the {sup 4}S{sub 3/2} state of Er{sup 3+} in the glassmore » ceramic was longer than that in the glass.« less
  • Tb{sup 3+}-Yb{sup 3+} codoped transparent oxyfluoride glass ceramics containing CaF{sub 2} nanocrystals were synthesized. The formation of CaF{sub 2} nanocrystals in the glass ceramics was confirmed by x-ray diffraction and high resolution transmission electron microscopy. The incorporation of Tb{sup 3+} and Yb{sup 3+} into CaF{sub 2} nanocrystal lattice was confirmed by energy dispersive spectroscopy. Infrared quantum cutting involving Yb{sup 3+} 950-1100 nm ({sup 2}F{sub 5/2}{yields}{sup 2}F{sub 7/2}) emission was achieved upon the excitation of {sup 5}D{sub 4} energy level of Tb{sup 3+} at 484 nm. The photoluminescence properties have been studied for these glass ceramics. Yb{sup 3+} concentration dependent quantummore » efficiency was calculated, and the maximum efficiency approaches 155% before reaching concentration quenching threshold.« less
  • Tm{sup 3+} and Ho{sup 3+} codoped transparent glass ceramic (GC) containing CaF{sub 2} nanocrystals were fabricated by melt-quenching and subsequent thermal treatment. X-ray diffraction and transmission electron microscopy analysis confirmed the precipitation of CaF{sub 2} nanocrystals among the glass matrix. Energy-dispersive x-ray spectroscopy results evidenced the incorporation of Tm{sup 3+} and Ho{sup 3+} into the CaF{sub 2} nanocrystals. Judd-Ofelt parameters were calculated based on the absorption spectra, the smaller {Omega}{sub 2} and larger {Omega}{sub 6} imply that Tm{sup 3+} and Ho{sup 3+} ions has entered into a symmetrical ionic crystal field. 2.02 {mu}m emission spectral of the GC samples weremore » recorded at room temperature with an excitation of 808 nm laser diode. The enhancement of the emission at 2.02 {mu}m in the GC samples could be attributed to more efficient cross relaxation process of Tm{sup 3+}:{sup 3}H{sub 4+}Tm{sup 3+}:{sup 3}H{sub 6}{yields}{sup 2}Tm{sup 3+}:{sup 3}H{sub 4}, and energy transfer from Tm{sup 3+} to Ho{sup 3+} benefited from the incorporation of rare earth ions into CaF{sub 2} nanocrystals.« less
  • Transparent glass ceramics in the system SiO{sub 2}-B{sub 2}O{sub 3}-PbO-CdO-PbF{sub 2}-CdF{sub 2}-YbF{sub 3}-ErF{sub 3} showing infrared to visible anti-Stokes (upconversion) luminescence are studied in the present work. The glass compositions have been optimized in order to reduce the melting temperature and, hence, to obtain laboratory scale samples with good optical quality. Erbium-doped nanoscale Pb{sub 4}Yb{sub 3}F{sub 17} crystals are precipitated in the precursor glasses during annealing at temperatures 30-40 K above T{sub g}. A kinetically self-constrained growth explains the nano sizes of the crystals. Both the Stokes and anti-Stokes luminescence spectra of glasses could be explained with clustering of themore » Yb{sup 3+} and Er{sup 3+} ions in fluorine-rich regions. At the annealing temperature these regions act as nucleation precursors. The crystal growth further enhances the local concentration of these ions. Consequently, a series of energy transfer and energy cross relaxation processes occurs between adjacent rare earth ions leading to the observed luminescence spectra of the glass ceramics studied. -- Graphical abstract: A highly viscous shell (shown in the picture in dark blue) is build around the growing crystal (white circles). When the shell's T{sub g} approaches the annealing temperature, the crystal growth is fully suppressed for kinetic reasons. The upconversion luminescence, resulting from the simultaneous absorption of two and even three infrared photons, is depicted schematically in the right part of the figure. Display Omitted Highlights: {yields} New oxyfluoride glass compositions with reduced melting temperature are formulated. {yields} The phase Pb{sub 4}Yb{sub 3}F{sub 17} doped with Er{sup 3+} ions crystallizes in these glasses. {yields} A kinetically self-constrained growth explains the nano sizes of the crystals. {yields} Clustering of Yb{sup 3+}, Er{sup 3+} and Pb{sup 2+} ions into fluorine-rich glass regions is observed. {yields} The luminescence of glass-ceramics is consistent with its structure.« less