The Experts below are selected from a list of 87 Experts worldwide ranked by ideXlab platform
Hiroyuki Inoue - One of the best experts on this subject based on the ideXlab platform.
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low phonon energies and wideband optical windows of la 2 o 3 ga 2 o 3 glasses prepared using an aerodynamic levitation technique
Scientific Reports, 2017Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Motoi Ueda, Hiroshi Yamamoto, Tastunori KawashimaAbstract:xLa2O3-(100 − x)Ga2O3 binary glasses were synthesized by an aerodynamic levitation technique. The Glass-Forming Region was found to be 20 ≤ x ≤ 57. The refractive indices were greater than 1.92 and increased linearly with increasing x. The polarizabilities of oxide ions were estimated to be 2.16–2.41 A3, indicating that the glasses were highly ionic. The glasses were transparent over a very wide range from the ultraviolet to the mid-infrared Region. The widest transparent window among the oxide glasses was from 270 nm to 10 μm at x = 55. From the Raman scattering spectra, a decrease in bridging oxide ions and an increase in non-bridging oxide ions were confirmed to occur with increasing La2O3 content. The maximum phonon energy was found to be approximately 650 cm−1, being one of the lowest among oxide glasses. These results show that La2O3-Ga2O3 binary glasses should be promising host materials for optical applications such as lenses, windows, and filters over a very wide wavelength range.
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thermal stability optical transmittance and refractive index dispersion of la2o3 nb2o5 al2o3 glasses
Journal of the American Ceramic Society, 2015Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:La2O3–Nb2O5–Al2O3 high-refractive-index glasses were fabricated by containerless processing, and the Glass-Forming Region was determined. The thermal stability, density, optical transmittance, and the refractive index dispersion of these glasses were investigated. All the glasses were colorless and transparent in the visible to near infrared (NIR) Region and had high refractive index with low wavelength dispersion. Some of these glasses were found to have significantly high Glass-Forming ability. These results indicate that the ternary glasses are suitable for optical applications in the visible to NIR Region. The effects of the substitution of Al2O3 for Nb2O5 on optical properties were discussed on the basis of the Drude–Voigt equation. It was suggested that the substitution of Al2O3 for Nb2O5 increased the molecular density and suppressed a decrease in the refractive index, even when both the average oscillator strength and inherent absorption wavelength decreased in La2O3–Nb2O5–Al2O3 glasses. These results are helpful for designing new optical glasses controlled to have a higher refractive index and lower wavelength dispersion.
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thermal and optical properties of la_2o_3 nb_2o_5 high refractive index glasses
Optical Materials Express, 2014Co-Authors: Atsunobu Masuno, Kohei Yoshimoto, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:(100−x)La2O3-xNb2O5 glasses with high refractive indices (>2.1) and low wavelength dispersion were prepared by containerless processing. All the glasses were colorless and transparent in the visible Region. The glass forming Region was divided into two Regions: a high-La2O3-content (39 ≤ x ≤ 42) Region and a high-Nb2O5-content (60 ≤ x ≤ 75) Region. The dependence of the physical properties on the composition for these two types of glasses was different, implying that the high-La2O3-content glasses (La glasses) and high-Nb2O5-content glasses (Nb glasses) were intrinsically different. A large difference in the molar volumes of the two types of glasses indicated that the Nb glasses were more densely packed than the La glasses. Furthermore, the oxygen polarizabilities estimated from the molar volumes and refractive indices were greater than 2.43 A3 for the La glasses, while those for the Nb glasses decreased from 2.43 A3 with decreasing x. The large oxygen polarizabilities, as compared to those of conventional optical glasses, indicate a particularly high degree of ionic character for the component elements in the glasses. These results suggest that both the La and Nb glasses are desirable materials for high-valued optics, such as lenses with high power and high resolution as well as wide viewing angles used for a digital camera in a smartphone.
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drastic connectivity change in high refractive index lanthanum niobate glasses
Chemistry of Materials, 2013Co-Authors: Atsunobu Masuno, Shinji Kohara, Alex C Hannon, Eugene Bychkov, Hiroyuki InoueAbstract:The highly ionic, high refractive index La2O3–Nb2O5 system has a La-rich glass forming Region and another Nb-rich glass forming Region. The La-rich and Nb-rich Regions have markedly different structural and physical properties. Structural analyses using diffraction and spectroscopic measurements combined with structural modeling show that the Nb-rich glass, which has unusually high oxygen packing density, is a network of distorted NbOn polyhedra with mainly corner-sharing, and LaOx polyhedra with both corner-sharing and edge-sharing. Contrastingly, in the La-rich glass, small-sized symmetrical NbOn polyhedra with a large amount of edge-sharing are inhomogenously distributed in the network of LaOx polyhedra. The drastic connectivity change of cation–oxygen polyhedra and the dense oxygen packing due to edge-sharing polyhedra contravene long-established rules of oxide glass formation. These results raise the possibility that novel higher refractive index with lower wavelength dispersion glasses, which contai...
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direct calculation of the physical properties of sodium borosilicate glass from its chemical composition using the concept of structural units
Journal of the American Ceramic Society, 2012Co-Authors: Hiroyuki Inoue, Atsunobu Masuno, Yasuhiro Watanabe, Keiichi Suzuki, Toru IsedaAbstract:The physical properties of sodium borosilicate glasses were calculated directly from their chemical compositions in the whole Glass-Forming Region. These properties included molar volume, refractive index, thermal expansion coefficient, elastic moduli, and glass transition temperature. The physical property values corresponding to the structural unit were estimated and then the calculation was carried out by accumulating the physical property values depending on the chemical composition of the glass. In the case of sodium borosilicate glass, the structural units are BO3/2, BO4/2Na,BO2/2ONa,BO1/2O2Na2,SiO4/2,SiO3/2ONa,SiO2/2O2Na2, and SiO1/2O3Na3. To conduct the calculation, the structural units’ physical property values were estimated by analyzing experimental data extracted from the database of glass properties, INTERGLAD. The calculated values were similar to the experimental data in the whole Glass-Forming Region. Furthermore, the calculation method provided, quantitatively, the structural units’ contributions to the glass’ physical properties. This study demonstrates that using the concept of structural units to calculate the physical properties of sodium borosilicate glass is a simple and powerful predictive tool.
Atsunobu Masuno - One of the best experts on this subject based on the ideXlab platform.
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low phonon energies and wideband optical windows of la 2 o 3 ga 2 o 3 glasses prepared using an aerodynamic levitation technique
Scientific Reports, 2017Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Motoi Ueda, Hiroshi Yamamoto, Tastunori KawashimaAbstract:xLa2O3-(100 − x)Ga2O3 binary glasses were synthesized by an aerodynamic levitation technique. The Glass-Forming Region was found to be 20 ≤ x ≤ 57. The refractive indices were greater than 1.92 and increased linearly with increasing x. The polarizabilities of oxide ions were estimated to be 2.16–2.41 A3, indicating that the glasses were highly ionic. The glasses were transparent over a very wide range from the ultraviolet to the mid-infrared Region. The widest transparent window among the oxide glasses was from 270 nm to 10 μm at x = 55. From the Raman scattering spectra, a decrease in bridging oxide ions and an increase in non-bridging oxide ions were confirmed to occur with increasing La2O3 content. The maximum phonon energy was found to be approximately 650 cm−1, being one of the lowest among oxide glasses. These results show that La2O3-Ga2O3 binary glasses should be promising host materials for optical applications such as lenses, windows, and filters over a very wide wavelength range.
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thermal stability optical transmittance and refractive index dispersion of la2o3 nb2o5 al2o3 glasses
Journal of the American Ceramic Society, 2015Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:La2O3–Nb2O5–Al2O3 high-refractive-index glasses were fabricated by containerless processing, and the Glass-Forming Region was determined. The thermal stability, density, optical transmittance, and the refractive index dispersion of these glasses were investigated. All the glasses were colorless and transparent in the visible to near infrared (NIR) Region and had high refractive index with low wavelength dispersion. Some of these glasses were found to have significantly high Glass-Forming ability. These results indicate that the ternary glasses are suitable for optical applications in the visible to NIR Region. The effects of the substitution of Al2O3 for Nb2O5 on optical properties were discussed on the basis of the Drude–Voigt equation. It was suggested that the substitution of Al2O3 for Nb2O5 increased the molecular density and suppressed a decrease in the refractive index, even when both the average oscillator strength and inherent absorption wavelength decreased in La2O3–Nb2O5–Al2O3 glasses. These results are helpful for designing new optical glasses controlled to have a higher refractive index and lower wavelength dispersion.
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thermal and optical properties of la_2o_3 nb_2o_5 high refractive index glasses
Optical Materials Express, 2014Co-Authors: Atsunobu Masuno, Kohei Yoshimoto, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:(100−x)La2O3-xNb2O5 glasses with high refractive indices (>2.1) and low wavelength dispersion were prepared by containerless processing. All the glasses were colorless and transparent in the visible Region. The glass forming Region was divided into two Regions: a high-La2O3-content (39 ≤ x ≤ 42) Region and a high-Nb2O5-content (60 ≤ x ≤ 75) Region. The dependence of the physical properties on the composition for these two types of glasses was different, implying that the high-La2O3-content glasses (La glasses) and high-Nb2O5-content glasses (Nb glasses) were intrinsically different. A large difference in the molar volumes of the two types of glasses indicated that the Nb glasses were more densely packed than the La glasses. Furthermore, the oxygen polarizabilities estimated from the molar volumes and refractive indices were greater than 2.43 A3 for the La glasses, while those for the Nb glasses decreased from 2.43 A3 with decreasing x. The large oxygen polarizabilities, as compared to those of conventional optical glasses, indicate a particularly high degree of ionic character for the component elements in the glasses. These results suggest that both the La and Nb glasses are desirable materials for high-valued optics, such as lenses with high power and high resolution as well as wide viewing angles used for a digital camera in a smartphone.
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drastic connectivity change in high refractive index lanthanum niobate glasses
Chemistry of Materials, 2013Co-Authors: Atsunobu Masuno, Shinji Kohara, Alex C Hannon, Eugene Bychkov, Hiroyuki InoueAbstract:The highly ionic, high refractive index La2O3–Nb2O5 system has a La-rich glass forming Region and another Nb-rich glass forming Region. The La-rich and Nb-rich Regions have markedly different structural and physical properties. Structural analyses using diffraction and spectroscopic measurements combined with structural modeling show that the Nb-rich glass, which has unusually high oxygen packing density, is a network of distorted NbOn polyhedra with mainly corner-sharing, and LaOx polyhedra with both corner-sharing and edge-sharing. Contrastingly, in the La-rich glass, small-sized symmetrical NbOn polyhedra with a large amount of edge-sharing are inhomogenously distributed in the network of LaOx polyhedra. The drastic connectivity change of cation–oxygen polyhedra and the dense oxygen packing due to edge-sharing polyhedra contravene long-established rules of oxide glass formation. These results raise the possibility that novel higher refractive index with lower wavelength dispersion glasses, which contai...
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direct calculation of the physical properties of sodium borosilicate glass from its chemical composition using the concept of structural units
Journal of the American Ceramic Society, 2012Co-Authors: Hiroyuki Inoue, Atsunobu Masuno, Yasuhiro Watanabe, Keiichi Suzuki, Toru IsedaAbstract:The physical properties of sodium borosilicate glasses were calculated directly from their chemical compositions in the whole Glass-Forming Region. These properties included molar volume, refractive index, thermal expansion coefficient, elastic moduli, and glass transition temperature. The physical property values corresponding to the structural unit were estimated and then the calculation was carried out by accumulating the physical property values depending on the chemical composition of the glass. In the case of sodium borosilicate glass, the structural units are BO3/2, BO4/2Na,BO2/2ONa,BO1/2O2Na2,SiO4/2,SiO3/2ONa,SiO2/2O2Na2, and SiO1/2O3Na3. To conduct the calculation, the structural units’ physical property values were estimated by analyzing experimental data extracted from the database of glass properties, INTERGLAD. The calculated values were similar to the experimental data in the whole Glass-Forming Region. Furthermore, the calculation method provided, quantitatively, the structural units’ contributions to the glass’ physical properties. This study demonstrates that using the concept of structural units to calculate the physical properties of sodium borosilicate glass is a simple and powerful predictive tool.
Yasuhiro Watanabe - One of the best experts on this subject based on the ideXlab platform.
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thermal stability optical transmittance and refractive index dispersion of la2o3 nb2o5 al2o3 glasses
Journal of the American Ceramic Society, 2015Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:La2O3–Nb2O5–Al2O3 high-refractive-index glasses were fabricated by containerless processing, and the Glass-Forming Region was determined. The thermal stability, density, optical transmittance, and the refractive index dispersion of these glasses were investigated. All the glasses were colorless and transparent in the visible to near infrared (NIR) Region and had high refractive index with low wavelength dispersion. Some of these glasses were found to have significantly high Glass-Forming ability. These results indicate that the ternary glasses are suitable for optical applications in the visible to NIR Region. The effects of the substitution of Al2O3 for Nb2O5 on optical properties were discussed on the basis of the Drude–Voigt equation. It was suggested that the substitution of Al2O3 for Nb2O5 increased the molecular density and suppressed a decrease in the refractive index, even when both the average oscillator strength and inherent absorption wavelength decreased in La2O3–Nb2O5–Al2O3 glasses. These results are helpful for designing new optical glasses controlled to have a higher refractive index and lower wavelength dispersion.
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thermal and optical properties of la_2o_3 nb_2o_5 high refractive index glasses
Optical Materials Express, 2014Co-Authors: Atsunobu Masuno, Kohei Yoshimoto, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:(100−x)La2O3-xNb2O5 glasses with high refractive indices (>2.1) and low wavelength dispersion were prepared by containerless processing. All the glasses were colorless and transparent in the visible Region. The glass forming Region was divided into two Regions: a high-La2O3-content (39 ≤ x ≤ 42) Region and a high-Nb2O5-content (60 ≤ x ≤ 75) Region. The dependence of the physical properties on the composition for these two types of glasses was different, implying that the high-La2O3-content glasses (La glasses) and high-Nb2O5-content glasses (Nb glasses) were intrinsically different. A large difference in the molar volumes of the two types of glasses indicated that the Nb glasses were more densely packed than the La glasses. Furthermore, the oxygen polarizabilities estimated from the molar volumes and refractive indices were greater than 2.43 A3 for the La glasses, while those for the Nb glasses decreased from 2.43 A3 with decreasing x. The large oxygen polarizabilities, as compared to those of conventional optical glasses, indicate a particularly high degree of ionic character for the component elements in the glasses. These results suggest that both the La and Nb glasses are desirable materials for high-valued optics, such as lenses with high power and high resolution as well as wide viewing angles used for a digital camera in a smartphone.
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direct calculation of the physical properties of sodium borosilicate glass from its chemical composition using the concept of structural units
Journal of the American Ceramic Society, 2012Co-Authors: Hiroyuki Inoue, Atsunobu Masuno, Yasuhiro Watanabe, Keiichi Suzuki, Toru IsedaAbstract:The physical properties of sodium borosilicate glasses were calculated directly from their chemical compositions in the whole Glass-Forming Region. These properties included molar volume, refractive index, thermal expansion coefficient, elastic moduli, and glass transition temperature. The physical property values corresponding to the structural unit were estimated and then the calculation was carried out by accumulating the physical property values depending on the chemical composition of the glass. In the case of sodium borosilicate glass, the structural units are BO3/2, BO4/2Na,BO2/2ONa,BO1/2O2Na2,SiO4/2,SiO3/2ONa,SiO2/2O2Na2, and SiO1/2O3Na3. To conduct the calculation, the structural units’ physical property values were estimated by analyzing experimental data extracted from the database of glass properties, INTERGLAD. The calculated values were similar to the experimental data in the whole Glass-Forming Region. Furthermore, the calculation method provided, quantitatively, the structural units’ contributions to the glass’ physical properties. This study demonstrates that using the concept of structural units to calculate the physical properties of sodium borosilicate glass is a simple and powerful predictive tool.
Kohei Yoshimoto - One of the best experts on this subject based on the ideXlab platform.
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low phonon energies and wideband optical windows of la 2 o 3 ga 2 o 3 glasses prepared using an aerodynamic levitation technique
Scientific Reports, 2017Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Motoi Ueda, Hiroshi Yamamoto, Tastunori KawashimaAbstract:xLa2O3-(100 − x)Ga2O3 binary glasses were synthesized by an aerodynamic levitation technique. The Glass-Forming Region was found to be 20 ≤ x ≤ 57. The refractive indices were greater than 1.92 and increased linearly with increasing x. The polarizabilities of oxide ions were estimated to be 2.16–2.41 A3, indicating that the glasses were highly ionic. The glasses were transparent over a very wide range from the ultraviolet to the mid-infrared Region. The widest transparent window among the oxide glasses was from 270 nm to 10 μm at x = 55. From the Raman scattering spectra, a decrease in bridging oxide ions and an increase in non-bridging oxide ions were confirmed to occur with increasing La2O3 content. The maximum phonon energy was found to be approximately 650 cm−1, being one of the lowest among oxide glasses. These results show that La2O3-Ga2O3 binary glasses should be promising host materials for optical applications such as lenses, windows, and filters over a very wide wavelength range.
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thermal stability optical transmittance and refractive index dispersion of la2o3 nb2o5 al2o3 glasses
Journal of the American Ceramic Society, 2015Co-Authors: Kohei Yoshimoto, Atsunobu Masuno, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:La2O3–Nb2O5–Al2O3 high-refractive-index glasses were fabricated by containerless processing, and the Glass-Forming Region was determined. The thermal stability, density, optical transmittance, and the refractive index dispersion of these glasses were investigated. All the glasses were colorless and transparent in the visible to near infrared (NIR) Region and had high refractive index with low wavelength dispersion. Some of these glasses were found to have significantly high Glass-Forming ability. These results indicate that the ternary glasses are suitable for optical applications in the visible to NIR Region. The effects of the substitution of Al2O3 for Nb2O5 on optical properties were discussed on the basis of the Drude–Voigt equation. It was suggested that the substitution of Al2O3 for Nb2O5 increased the molecular density and suppressed a decrease in the refractive index, even when both the average oscillator strength and inherent absorption wavelength decreased in La2O3–Nb2O5–Al2O3 glasses. These results are helpful for designing new optical glasses controlled to have a higher refractive index and lower wavelength dispersion.
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thermal and optical properties of la_2o_3 nb_2o_5 high refractive index glasses
Optical Materials Express, 2014Co-Authors: Atsunobu Masuno, Kohei Yoshimoto, Hiroyuki Inoue, Yasuhiro WatanabeAbstract:(100−x)La2O3-xNb2O5 glasses with high refractive indices (>2.1) and low wavelength dispersion were prepared by containerless processing. All the glasses were colorless and transparent in the visible Region. The glass forming Region was divided into two Regions: a high-La2O3-content (39 ≤ x ≤ 42) Region and a high-Nb2O5-content (60 ≤ x ≤ 75) Region. The dependence of the physical properties on the composition for these two types of glasses was different, implying that the high-La2O3-content glasses (La glasses) and high-Nb2O5-content glasses (Nb glasses) were intrinsically different. A large difference in the molar volumes of the two types of glasses indicated that the Nb glasses were more densely packed than the La glasses. Furthermore, the oxygen polarizabilities estimated from the molar volumes and refractive indices were greater than 2.43 A3 for the La glasses, while those for the Nb glasses decreased from 2.43 A3 with decreasing x. The large oxygen polarizabilities, as compared to those of conventional optical glasses, indicate a particularly high degree of ionic character for the component elements in the glasses. These results suggest that both the La and Nb glasses are desirable materials for high-valued optics, such as lenses with high power and high resolution as well as wide viewing angles used for a digital camera in a smartphone.
Liangming Xiong - One of the best experts on this subject based on the ideXlab platform.
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optical properties thermal stability and forming Region of high refractive index la2o3 tio2 nb2o5 glasses
Journal of the American Ceramic Society, 2018Co-Authors: Zhaozhao Mao, Chaoyue Wang, Xiaojie Zheng, Liangming XiongAbstract:The high refractive index La2O3–TiO2–Nb2O5 glasses were prepared by containerless processing, and the Glass-Forming Region was determined. The refractive index showed the range from 2.20 to 2.32, and the values were much higher than those of most optical glasses. The completely miscible 30LaO3/2–(70−x)TiO2–xNbO5/2 (0≤x≤70) system was fabricated to study the compositional dependence of refractive index and optical transmittance. The crucial determinants of the refractive index of oxide glasses, oxygen molar volume and electronic polarizability of oxygen ions were calculated. The principle of additivity of glass properties was suitable for the calculation of refractive index between glass and compositional oxides. All the glasses were colorless and transparent in the visible to 6.5 μm middle infrared (MIR) Region. These results are useful for designing new optical glasses with high refractive index and low wavelength dispersion in wide optical window. This article is protected by copyright. All rights reserved.