Crystallization kinetics and spectroscopic investigations on Tb{sup 3+} and Yb{sup 3+} codoped glass ceramics containing CaF{sub 2} nanocrystals

Journal Article · Thu Nov 01 04:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2802289· OSTI ID:21064429

Lihui, Huang; Guanshi, Qin; Arai, Yusuke; Jose, Rajan; Suzuki, Takenobu; Ohishi, Yasutake; Yamashita, Tatsuya; Akimoto, Yusuke ^[1]

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1. Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511 (Japan)

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. 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.

• OSTI ID: 21064429
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 102; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
CALCIUM FLUORIDES
CALORIMETRY
CERAMICS
CRYSTAL GROWTH
CRYSTALLIZATION
EMISSION SPECTRA
GLASS
HEAT TREATMENTS
NANOSTRUCTURES
OXYFLUORIDES
PHOTOLUMINESCENCE
SILICON COMPOUNDS
TEMPERATURE RANGE 0273-0400 K
TERBIUM COMPOUNDS
TERBIUM IONS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
YTTERBIUM COMPOUNDS
YTTERBIUM IONS