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E. Moser - One of the best experts on this subject based on the ideXlab platform.

  • Rare-earth-activated Glass–Ceramic waveguides
    Optical Materials, 2010
    Co-Authors: S. Berneschi, G. Alombert-goget, S. Soria, G.c. Righini, A. Chiappini, A. Chiasera, Y. Jestin, M. Ferrari, S. Guddala, E. Moser
    Abstract:

    This work presents a short review of the activity performed in developing sol–gel-derived SiO2–HfO2 and SiO2–SnO2 Glass–Ceramic waveguides activated by Er3+ and Eu3+ ions, respectively. Fabrication by top-down and bottom-up techniques is reported and optical and spectroscopic assessment of Glass Ceramic waveguides is discussed. Luminescence enhancement is demonstrated. Refractive index modulation upon UV exposure is measured in SiO2–SnO2 film.

Akihiko Sakamoto - One of the best experts on this subject based on the ideXlab platform.

  • Glass-Ceramic LiFePO4 for lithium-ion rechargeable battery
    Solid State Ionics, 2012
    Co-Authors: Tomohiro Nagakane, Hideo Yamauchi, K. Yuki, Masahiko Ohji, Akihiko Sakamoto, Takayuki Komatsu, Tsuyoshi Honma, M. Zou, Gumjae Park, Tetsuo Sakai
    Abstract:

    Abstract Glass-Ceramic LiFePO 4 was synthesized through the crystallization of Glass powder prepared by melting low-cost raw materials in ambient air. To obtain the homogeneous precursor Glass, the addition of a small amount of Nb 2 O 5 was effective. Ferric ions in the precursor Glass were reduced and precipitated as LiFePO 4 through the heat treatment of a mixture of the Glass powder and a carbon source. The obtained Glass-Ceramic particles contained a LiFePO 4 crystalline phase and a carbon-containing surface amorphous layer with a thickness of about 20 nm. A lithium-ion rechargeable battery fabricated with the Glass-Ceramic powder showed better high-rate performance than that of a battery made using commercial LiFePO 4 Ceramic powder. The better performance of the battery with the Glass-Ceramic is attributed to the existence of the surface amorphous layer. This synthesis process, consisting of Glass melting in air and the subsequent crystallization of Glass powder, has the potential to be used for the large-scale continuous production of high-performance LiFePO 4 .

  • β spodumene Glass Ceramic with anomalous low thermal expansion
    Advanced Materials Research, 2008
    Co-Authors: Akihiko Sakamoto, Yusuke Himei, Yoshio Hashibe
    Abstract:

    To survey new method for controlling thermal expansion of Glass-Ceramic material, we studied the coefficient of thermal expansion (CTE) and the microstructure of β-spodumene Glass-Ceramics. We found that the CTE of the β-spodumene Glass-Ceramics is remarkably reduced by introducing interstices at the boundary between the crystalline and Glass phases. Despite its relatively low crystallinity (45vol%), a newly developed Glass-Ceramic showed an anomalous low thermal expansion of 7x10-7 /oC, which compares to that of silica Glass. The mechanical strength of this Glass-Ceramic was at the same level as that of natural stones: marble and granite.

  • yag Glass Ceramic phosphor for white led i background and development
    Proceedings of SPIE, 2005
    Co-Authors: Shunsuke Fujita, Akihiko Sakamoto, Satoru Yoshihara, Shigeru Yamamoto, Setsuhisa Tanabe
    Abstract:

    We have developed a Ce:YAG (Y3Al5O12) Glass-Ceramic phosphor for the white LED. The Glass-Ceramic phosphor was obtained by a heat treatment of a Ce-doped SiO2-Al2O3-Y2O3 mother Glass between 1200°C and 1500°C for the prescribed time of period. We confirmed that, by XRD measurements, only YAG crystal precipitated in the mother Glass after the heat treatment. It was shown from SEM observation that the YAG crystals with a grain size of approximately 20μm were uniformly dispersed in the Glass matrix. The yellow emission, around 540nm in wavelength, was observed from the Glass-Ceramic phosphor, when it was excited by a blue LED (465nm). The white light due to the mix of yellow and blue light was observed from the Glass-Ceramic plate with a thickness of 0.5mm. The YAG Glass-Ceramic phosphor showed a high-temperature resistance and a good performance in a damp heat test. Moreover, a higher thermal conductivity of 2.18 Wm-1K-1 and bending strength of 125MPa were observed compared with a conventional soda-lime Glass or an epoxy resin. In addition, since the YAG Glass-Ceramic phosphor can be formed in a plate-like shape, there is no need to be sealed in resins for the fabrication of the LED devices. Therefore, it is expected that this newly developed Glass-Ceramic phosphor is a promising candidate for the realization of resin-free, high-temperature and high-humidity resistant, long-life white LED devices.

G. Alombert-goget - One of the best experts on this subject based on the ideXlab platform.

  • Rare earth–activated Glass-Ceramic in planar format
    Optical Engineering, 2011
    Co-Authors: Alessandro Chiasera, G. Alombert-goget, Maurizio Ferrari, Simone Berneschi, Stefano Pelli, Brigitte Boulard, Claire Duverger Arfuso
    Abstract:

    Rare earth-activated Glass-Ceramic waveguides constitute a potential significant system to behave as an effective optical medium for light propagation and luminescence enhancement. We present a review on fabrication and optical, structural, and spectroscopic characterization of some kind of rare earth activated oxide Glass-Ceramic waveguides, obtained by sol-gel route with both bottom-up and top-down approaches, and fluoride Glass-Ceramic waveguides fabricated by physical vapor deposition.

  • Rare-earth-activated Glass–Ceramic waveguides
    Optical Materials, 2010
    Co-Authors: S. Berneschi, G. Alombert-goget, S. Soria, G.c. Righini, A. Chiappini, A. Chiasera, Y. Jestin, M. Ferrari, S. Guddala, E. Moser
    Abstract:

    This work presents a short review of the activity performed in developing sol–gel-derived SiO2–HfO2 and SiO2–SnO2 Glass–Ceramic waveguides activated by Er3+ and Eu3+ ions, respectively. Fabrication by top-down and bottom-up techniques is reported and optical and spectroscopic assessment of Glass Ceramic waveguides is discussed. Luminescence enhancement is demonstrated. Refractive index modulation upon UV exposure is measured in SiO2–SnO2 film.

  • Glass-Ceramic waveguides: Fabrication and properties
    2010 12th International Conference on Transparent Optical Networks, 2010
    Co-Authors: Sriram Guddala, Alessandro Chiasera, G. Alombert-goget, Maurizio Ferrari, Simone Berneschi, Cristina Armellini, Andrea Chiappini, Maurizio Mazzola, Giancarlo C. Righini, Enrico Moser
    Abstract:

    Er3+-acticated silica-hafnia Glass-Ceramic waveguides were fabricated by bottom-up and top-down approaches. The pros and cons of the procedures in terms of optical, spectroscopic and structural properties are reported, in particular regarding attenuation coefficient, NIR emission, and local environment for the rare-earth ions. The results confirm the significance of SiO 2 -HfO 2 Glass Ceramic waveguides as a viable photonic system.

S. Berneschi - One of the best experts on this subject based on the ideXlab platform.

  • Rare-earth-activated Glass–Ceramic waveguides
    Optical Materials, 2010
    Co-Authors: S. Berneschi, G. Alombert-goget, S. Soria, G.c. Righini, A. Chiappini, A. Chiasera, Y. Jestin, M. Ferrari, S. Guddala, E. Moser
    Abstract:

    This work presents a short review of the activity performed in developing sol–gel-derived SiO2–HfO2 and SiO2–SnO2 Glass–Ceramic waveguides activated by Er3+ and Eu3+ ions, respectively. Fabrication by top-down and bottom-up techniques is reported and optical and spectroscopic assessment of Glass Ceramic waveguides is discussed. Luminescence enhancement is demonstrated. Refractive index modulation upon UV exposure is measured in SiO2–SnO2 film.

Monica Ferraris - One of the best experts on this subject based on the ideXlab platform.

  • Thermal cycling and ageing of a Glass-Ceramic sealant for planar SOFCs
    International Journal of Hydrogen Energy, 2011
    Co-Authors: Federico Smeacetto, Andreas Chrysanthou, Milena Salvo, Tomasz Moskalewicz, F. D’herin Bytner, Lakshmi Chandru Ajitdoss, Monica Ferraris
    Abstract:

    Abstract Thermal cycling and thermal ageing tests were performed on Crofer22APU/Glass-Ceramic/Anode-Supported-Electrolyte (ASE) joined samples in air at the SOFC operating temperature of 800 °C. The Crofer22APU had been polished and preoxidised at 900 °C for 2 h. The diffusion behaviour at the two interfaces was examined and revealed slight diffusion of chromium and manganese from Crofer22APU into the Glass-Ceramic. No interactions, failure or crack formation were observed at the Crofer22APU/Glass-Ceramic interface and between the Glass-Ceramic and YSZ.