The Experts below are selected from a list of 139803 Experts worldwide ranked by ideXlab platform
Kheirreddine Lebbou - One of the best experts on this subject based on the ideXlab platform.
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structure and white led properties of ce doped yag al2o3 Eutectics grown by the micro pulling down method
CrystEngComm, 2019Co-Authors: Qingsong Song, Xiaodong Xu, Xiangshai Bu, Dongzhen Li, Yinzhen Wang, Jun Xu, Kheirreddine LebbouAbstract:A series of Ce-doped YAG-Al2O3 Eutectics were grown by the micro-pulling-down (μ-PD) method, for the purpose of high power white light emitting diodes. The eutectic structure was investigated. A calibrated integrating sphere spectrometer setup was used to measure the white LED properties of eutectic samples. The CIE color coordinates can be regulated easily by altering the Ce3+ doping concentration and sample thickness of the Ce:YAG-Al2O3 Eutectics. A 1 W white LED device based on Ce:YAG-Al2O3 Eutectics at a rated current of 350 mA emitted a bright white light with a CIE coordinate of (0.319, 0.334), a luminous efficacy of 83.0 lm W−1 and a Duv value of 0.003. The results showed that Ce:YAG-Al2O3 Eutectics have better luminescence properties than commercial powder phosphors at a high current density.
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Structure and white LED properties of Ce-doped YAG-Al 2 O 3 Eutectics grown by the micro-pulling-down method
CrystEngComm, 2019Co-Authors: Qingsong Song, Yinzhen Wang, Jian Liu, Peng Liu, Kheirreddine LebbouAbstract:A series of Ce-doped YAG-Al2O3 Eutectics were grown by the micro-pulling-down (μ-PD) method, for the purpose of high power white light emitting diodes. The eutectic structure was investigated. A calibrated integrating sphere spectrometer setup was used to measure the white LED properties of eutectic samples. The CIE color coordinates can be regulated easily by altering the Ce3+ doping concentration and sample thickness of the Ce:YAG-Al2O3 Eutectics. A 1 W white LED device based on Ce:YAG-Al2O3 Eutectics at a rated current of 350 mA emitted a bright white light with a CIE coordinate of (0.319, 0.334), a luminous efficacy of 83.0 lm W−1 and a Duv value of 0.003. The results showed that Ce:YAG-Al2O3 Eutectics have better luminescence properties than commercial powder phosphors at a high current density.
Feng Liu - One of the best experts on this subject based on the ideXlab platform.
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Phase selection and re-melting-induced anomalous Eutectics in undercooled Ni–38 wt% Si alloys
Journal of Materials Science, 2016Co-Authors: Cun Lai, Haifeng Wang, Jinsong Yang, Xi Zhang, Feng LiuAbstract:The Ni–38 wt% Si alloy whose eutectic products are two stoichiometric intermetallic compounds (i.e., NiSi and NiSi2) was undercooled by the melt fluxing technique. After in situ observations of the recalescence processes using a high-speed camera and by electron back-scattering diffraction analysis of the solidification microstructures, the crystal growth velocities, phase selection, and microstructure evolutions were studied. Due to a growth-controlled mechanism, the primary phase changes from the NiSi to the NiSi2 phase at a critical undercooling ΔT ≈ 48 K. Even in the absence of the driving force of chemical superheating, the transition from regular Eutectics to anomalous Eutectics happens. The reason is that the single-phase dendrite of NiSi2 phase solidifies firstly and then the NiSi phase grows epitaxially to form an uncoupled eutectic-dendrite at high undercooling. The present work provides further experimental evidences for the dual origins of anomalous Eutectics (e.g., uncoupled eutectic-dendrite growth during the recalescence stage and coupled lamellar eutectic growth at low undercooling during the post-recalescence stage) and is helpful for understanding of non-equilibrium phenomena in undercooled melts.
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phase selection and re melting induced anomalous Eutectics in undercooled ni 38 wt si alloys
Journal of Materials Science, 2016Co-Authors: Cun Lai, Haifeng Wang, Jinsong Yang, Xi Zhang, Feng LiuAbstract:The Ni–38 wt% Si alloy whose eutectic products are two stoichiometric intermetallic compounds (i.e., NiSi and NiSi2) was undercooled by the melt fluxing technique. After in situ observations of the recalescence processes using a high-speed camera and by electron back-scattering diffraction analysis of the solidification microstructures, the crystal growth velocities, phase selection, and microstructure evolutions were studied. Due to a growth-controlled mechanism, the primary phase changes from the NiSi to the NiSi2 phase at a critical undercooling ΔT ≈ 48 K. Even in the absence of the driving force of chemical superheating, the transition from regular Eutectics to anomalous Eutectics happens. The reason is that the single-phase dendrite of NiSi2 phase solidifies firstly and then the NiSi phase grows epitaxially to form an uncoupled eutectic-dendrite at high undercooling. The present work provides further experimental evidences for the dual origins of anomalous Eutectics (e.g., uncoupled eutectic-dendrite growth during the recalescence stage and coupled lamellar eutectic growth at low undercooling during the post-recalescence stage) and is helpful for understanding of non-equilibrium phenomena in undercooled melts.
Qingsong Song - One of the best experts on this subject based on the ideXlab platform.
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structure and white led properties of ce doped yag al2o3 Eutectics grown by the micro pulling down method
CrystEngComm, 2019Co-Authors: Qingsong Song, Xiaodong Xu, Xiangshai Bu, Dongzhen Li, Yinzhen Wang, Jun Xu, Kheirreddine LebbouAbstract:A series of Ce-doped YAG-Al2O3 Eutectics were grown by the micro-pulling-down (μ-PD) method, for the purpose of high power white light emitting diodes. The eutectic structure was investigated. A calibrated integrating sphere spectrometer setup was used to measure the white LED properties of eutectic samples. The CIE color coordinates can be regulated easily by altering the Ce3+ doping concentration and sample thickness of the Ce:YAG-Al2O3 Eutectics. A 1 W white LED device based on Ce:YAG-Al2O3 Eutectics at a rated current of 350 mA emitted a bright white light with a CIE coordinate of (0.319, 0.334), a luminous efficacy of 83.0 lm W−1 and a Duv value of 0.003. The results showed that Ce:YAG-Al2O3 Eutectics have better luminescence properties than commercial powder phosphors at a high current density.
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Structure and white LED properties of Ce-doped YAG-Al 2 O 3 Eutectics grown by the micro-pulling-down method
CrystEngComm, 2019Co-Authors: Qingsong Song, Yinzhen Wang, Jian Liu, Peng Liu, Kheirreddine LebbouAbstract:A series of Ce-doped YAG-Al2O3 Eutectics were grown by the micro-pulling-down (μ-PD) method, for the purpose of high power white light emitting diodes. The eutectic structure was investigated. A calibrated integrating sphere spectrometer setup was used to measure the white LED properties of eutectic samples. The CIE color coordinates can be regulated easily by altering the Ce3+ doping concentration and sample thickness of the Ce:YAG-Al2O3 Eutectics. A 1 W white LED device based on Ce:YAG-Al2O3 Eutectics at a rated current of 350 mA emitted a bright white light with a CIE coordinate of (0.319, 0.334), a luminous efficacy of 83.0 lm W−1 and a Duv value of 0.003. The results showed that Ce:YAG-Al2O3 Eutectics have better luminescence properties than commercial powder phosphors at a high current density.
Cun Lai - One of the best experts on this subject based on the ideXlab platform.
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Anomalous Eutectics in intermediately and highly undercooled Ni-29.8at.%Si eutectic alloy
Journal of Crystal Growth, 2018Co-Authors: Fan Zhang, Cun Lai, Jianbao Zhang, Yachan Zhang, Qing Zhou, Haifeng WangAbstract:Abstract The transition from regular Eutectics to anomalous Eutectics is a well-known non-equilibrium phenomenon for undercooled eutectic alloys, the mechanism of which has been studied extensively but is still controversial. In this work, a Ni-29.8at.%Si eutectic alloy, as an ideal modeling system whose eutectic products are two stoichiometric intermetallic compounds, whose rapid solidification does not suffer any phase-selection and whose transformation path does not include any solid-state phase transformation, was undercooled by a melt fluxing technique and observed in-situ by a high-speed camera. A common transition from uncoupled Eutectics to anomalous Eutectics and a unique transition from uncoupled coarse lamellar-Eutectics to anomalous Eutectics were found at intermediate and high undercooling, respectively. The formation of coarse lamellar-Eutectics is highly related to the abrupt increase of growth velocity at ΔT ≈ 149 K, which is accompanied by a transition from dual-recalescence to single-recalescence. An electron back-scattering diffraction analysis shows that epitaxial growth of the second δ-Ni2Si phase on the primary γ-Ni31Si12 phase follows a particular eutectic orientation relationship. Anomalous Eutectics were concluded to be formed by uncoupled eutectic growth with the reduction of interfacial energy but not chemical superheating as the driving force.
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Phase selection and re-melting-induced anomalous Eutectics in undercooled Ni–38 wt% Si alloys
Journal of Materials Science, 2016Co-Authors: Cun Lai, Haifeng Wang, Jinsong Yang, Xi Zhang, Feng LiuAbstract:The Ni–38 wt% Si alloy whose eutectic products are two stoichiometric intermetallic compounds (i.e., NiSi and NiSi2) was undercooled by the melt fluxing technique. After in situ observations of the recalescence processes using a high-speed camera and by electron back-scattering diffraction analysis of the solidification microstructures, the crystal growth velocities, phase selection, and microstructure evolutions were studied. Due to a growth-controlled mechanism, the primary phase changes from the NiSi to the NiSi2 phase at a critical undercooling ΔT ≈ 48 K. Even in the absence of the driving force of chemical superheating, the transition from regular Eutectics to anomalous Eutectics happens. The reason is that the single-phase dendrite of NiSi2 phase solidifies firstly and then the NiSi phase grows epitaxially to form an uncoupled eutectic-dendrite at high undercooling. The present work provides further experimental evidences for the dual origins of anomalous Eutectics (e.g., uncoupled eutectic-dendrite growth during the recalescence stage and coupled lamellar eutectic growth at low undercooling during the post-recalescence stage) and is helpful for understanding of non-equilibrium phenomena in undercooled melts.
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phase selection and re melting induced anomalous Eutectics in undercooled ni 38 wt si alloys
Journal of Materials Science, 2016Co-Authors: Cun Lai, Haifeng Wang, Jinsong Yang, Xi Zhang, Feng LiuAbstract:The Ni–38 wt% Si alloy whose eutectic products are two stoichiometric intermetallic compounds (i.e., NiSi and NiSi2) was undercooled by the melt fluxing technique. After in situ observations of the recalescence processes using a high-speed camera and by electron back-scattering diffraction analysis of the solidification microstructures, the crystal growth velocities, phase selection, and microstructure evolutions were studied. Due to a growth-controlled mechanism, the primary phase changes from the NiSi to the NiSi2 phase at a critical undercooling ΔT ≈ 48 K. Even in the absence of the driving force of chemical superheating, the transition from regular Eutectics to anomalous Eutectics happens. The reason is that the single-phase dendrite of NiSi2 phase solidifies firstly and then the NiSi phase grows epitaxially to form an uncoupled eutectic-dendrite at high undercooling. The present work provides further experimental evidences for the dual origins of anomalous Eutectics (e.g., uncoupled eutectic-dendrite growth during the recalescence stage and coupled lamellar eutectic growth at low undercooling during the post-recalescence stage) and is helpful for understanding of non-equilibrium phenomena in undercooled melts.
Yinzhen Wang - One of the best experts on this subject based on the ideXlab platform.
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structure and white led properties of ce doped yag al2o3 Eutectics grown by the micro pulling down method
CrystEngComm, 2019Co-Authors: Qingsong Song, Xiaodong Xu, Xiangshai Bu, Dongzhen Li, Yinzhen Wang, Jun Xu, Kheirreddine LebbouAbstract:A series of Ce-doped YAG-Al2O3 Eutectics were grown by the micro-pulling-down (μ-PD) method, for the purpose of high power white light emitting diodes. The eutectic structure was investigated. A calibrated integrating sphere spectrometer setup was used to measure the white LED properties of eutectic samples. The CIE color coordinates can be regulated easily by altering the Ce3+ doping concentration and sample thickness of the Ce:YAG-Al2O3 Eutectics. A 1 W white LED device based on Ce:YAG-Al2O3 Eutectics at a rated current of 350 mA emitted a bright white light with a CIE coordinate of (0.319, 0.334), a luminous efficacy of 83.0 lm W−1 and a Duv value of 0.003. The results showed that Ce:YAG-Al2O3 Eutectics have better luminescence properties than commercial powder phosphors at a high current density.
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Structure and white LED properties of Ce-doped YAG-Al 2 O 3 Eutectics grown by the micro-pulling-down method
CrystEngComm, 2019Co-Authors: Qingsong Song, Yinzhen Wang, Jian Liu, Peng Liu, Kheirreddine LebbouAbstract:A series of Ce-doped YAG-Al2O3 Eutectics were grown by the micro-pulling-down (μ-PD) method, for the purpose of high power white light emitting diodes. The eutectic structure was investigated. A calibrated integrating sphere spectrometer setup was used to measure the white LED properties of eutectic samples. The CIE color coordinates can be regulated easily by altering the Ce3+ doping concentration and sample thickness of the Ce:YAG-Al2O3 Eutectics. A 1 W white LED device based on Ce:YAG-Al2O3 Eutectics at a rated current of 350 mA emitted a bright white light with a CIE coordinate of (0.319, 0.334), a luminous efficacy of 83.0 lm W−1 and a Duv value of 0.003. The results showed that Ce:YAG-Al2O3 Eutectics have better luminescence properties than commercial powder phosphors at a high current density.
