The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Akira J Ikushima - One of the best experts on this subject based on the ideXlab platform.
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Structural relaxation in sputter-deposited Silica Glass
Journal of Non-crystalline Solids, 2006Co-Authors: Tomohiro Hirose, Kazuya Saito, Akira J IkushimaAbstract:Abstract We investigated structural relaxation below the Glass transition temperature in sputter-deposited Silica Glass. Structural relaxation was obtained from annealing behavior of the IR reflection structural band position. Results were compared with that of bulk Silica Glass. Results showed the following. (1) The structural relaxation time is 106 times shorter than that of bulk Silica Glass. (2) The activation energy is close to that of bulk Silica Glass. (3) Once the structural relaxation reaches a steady state, the structure of Silica Glass film resembles that of bulk Silica Glass.
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Structural Relaxations in Silica Glass
AIP Conference Proceedings, 2004Co-Authors: Akira J Ikushima, Kazuya Saito, Hiroshi KakiuchidaAbstract:Structural relaxation is a key factor to control structure and physical properties of Silica Glass. We investigated structural disorder during structural relaxation processes, and have found that the disorder reduces with decreasing the fictive temperature. Consequently, various optical properties, e.g., Rayleigh light scattering, Urbach edge, and formation of photo‐induced defects are straightforwardly correlated to the fictive temperature. The structural relaxation has been tentatively analyzed assuming two processes: main‐and sub‐relaxations. Both processes seem to be encouraged tremendously by the halogen doping, especially with fluorine and chlorine. Both main‐ and sub‐relaxations can be shortened by the order of 5–6 orders of magnitude by doping of several percents of F. The result implies that a great possibility of breakthrough that Silica Glass can be more transparent, as the density fluctuation in Silica Glass that is frozen at the fictive temperature can be reduced through the relaxations. This in turn means that the fiber drawing process under the best‐optimized temperature condition should yield much more lucent fibers. We have also found that UV absorption edge is very much affected by the structural relaxation. The absorption edge shifts to shorter wavelengths with decreasing the fictive temperature.
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Fictive-temperature dependence of structural relaxation in Silica Glass
Journal of Applied Physics, 2003Co-Authors: Hiroshi Kakiuchida, Kazuya Saito, Akira J IkushimaAbstract:To clarify the factors that determine the structural relaxations in Silica Glass, the influence of fictive temperature on the relaxation process was investigated. It was found that the relaxations at different heat-treatment temperatures are enhanced with a rise in the fictive temperature. The structural relaxation is not simply the Maxwell process that is determined only by the heat-treatment temperature. Since the density of Silica Glass increases with a rise in the fictive temperature, the mechanism of the aforementioned enhancement cannot be understood by the free volume theory, which has often been utilized for explaining structural relaxations in many Glass formers. The present results reveal the significance of the fictive temperature in understanding the structural relaxation phenomenon in Silica Glass.
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Rayleigh scattering in fluorine-doped Silica Glass
Materials and Devices for Optical and Wireless Communications, 2002Co-Authors: Hiroshi Kakiuchida, Kazuya Saito, Akira J IkushimaAbstract:The Rayleigh scattering intensity in fluorine-doped Silica Glass was found to decrease very effectively with lowering frozen-in temperature of the Glass, so-called the fictive temperature, while such reduction becomes less in samples with higher fluorine concentrations. The present result implies that the Rayleigh scattering in fluorine-doped Silica Glass is affected by concentration fluctuation besides density fluctuation. From the result, we established a simulated annealing effect of the Glass on reduction of the Rayleigh scattering intensity.
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Silica Glass for photonics
Optoelectronic Information Systems and Processing, 2001Co-Authors: Akira J Ikushima, Hiroshi Kakiuchida, Kazuya SaitoAbstract:Recent studies on Silica Glass as a photonic material will be described. With regard to the structural disorder, investigations have been made to improve transparency and to shift the optical absorption edge in the ultraviolet towards shorter wavelengths. Remarkable advances have been achieved in the understanding of both light scattering, which is a dominant factor in the optical losses in Silica fibers, and the absorption edge. Freezing of the structural disorder was observed, and structural relaxations are found to be important for improving the transparency, whereas for the absorption edge thermal vibration effects seem to be more predominant than the structural disorder. From the results, the present authors have tried to control the structural relaxation for developing Silica Glass with an ultimate optical transparency, finding that a very tiny amount of the proper impurity species gives rise to structural subrelaxations, which are effective in reducing the Rayleigh scattering. The scattering was reduced by 13% by addition of only 10 wt.ppm Na 2 O, for example.
Kazuya Saito - One of the best experts on this subject based on the ideXlab platform.
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Structural relaxation in sputter-deposited Silica Glass
Journal of Non-crystalline Solids, 2006Co-Authors: Tomohiro Hirose, Kazuya Saito, Akira J IkushimaAbstract:Abstract We investigated structural relaxation below the Glass transition temperature in sputter-deposited Silica Glass. Structural relaxation was obtained from annealing behavior of the IR reflection structural band position. Results were compared with that of bulk Silica Glass. Results showed the following. (1) The structural relaxation time is 106 times shorter than that of bulk Silica Glass. (2) The activation energy is close to that of bulk Silica Glass. (3) Once the structural relaxation reaches a steady state, the structure of Silica Glass film resembles that of bulk Silica Glass.
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Structural Relaxations in Silica Glass
AIP Conference Proceedings, 2004Co-Authors: Akira J Ikushima, Kazuya Saito, Hiroshi KakiuchidaAbstract:Structural relaxation is a key factor to control structure and physical properties of Silica Glass. We investigated structural disorder during structural relaxation processes, and have found that the disorder reduces with decreasing the fictive temperature. Consequently, various optical properties, e.g., Rayleigh light scattering, Urbach edge, and formation of photo‐induced defects are straightforwardly correlated to the fictive temperature. The structural relaxation has been tentatively analyzed assuming two processes: main‐and sub‐relaxations. Both processes seem to be encouraged tremendously by the halogen doping, especially with fluorine and chlorine. Both main‐ and sub‐relaxations can be shortened by the order of 5–6 orders of magnitude by doping of several percents of F. The result implies that a great possibility of breakthrough that Silica Glass can be more transparent, as the density fluctuation in Silica Glass that is frozen at the fictive temperature can be reduced through the relaxations. This in turn means that the fiber drawing process under the best‐optimized temperature condition should yield much more lucent fibers. We have also found that UV absorption edge is very much affected by the structural relaxation. The absorption edge shifts to shorter wavelengths with decreasing the fictive temperature.
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Fictive-temperature dependence of structural relaxation in Silica Glass
Journal of Applied Physics, 2003Co-Authors: Hiroshi Kakiuchida, Kazuya Saito, Akira J IkushimaAbstract:To clarify the factors that determine the structural relaxations in Silica Glass, the influence of fictive temperature on the relaxation process was investigated. It was found that the relaxations at different heat-treatment temperatures are enhanced with a rise in the fictive temperature. The structural relaxation is not simply the Maxwell process that is determined only by the heat-treatment temperature. Since the density of Silica Glass increases with a rise in the fictive temperature, the mechanism of the aforementioned enhancement cannot be understood by the free volume theory, which has often been utilized for explaining structural relaxations in many Glass formers. The present results reveal the significance of the fictive temperature in understanding the structural relaxation phenomenon in Silica Glass.
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Rayleigh scattering in fluorine-doped Silica Glass
Materials and Devices for Optical and Wireless Communications, 2002Co-Authors: Hiroshi Kakiuchida, Kazuya Saito, Akira J IkushimaAbstract:The Rayleigh scattering intensity in fluorine-doped Silica Glass was found to decrease very effectively with lowering frozen-in temperature of the Glass, so-called the fictive temperature, while such reduction becomes less in samples with higher fluorine concentrations. The present result implies that the Rayleigh scattering in fluorine-doped Silica Glass is affected by concentration fluctuation besides density fluctuation. From the result, we established a simulated annealing effect of the Glass on reduction of the Rayleigh scattering intensity.
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Silica Glass for photonics
Optoelectronic Information Systems and Processing, 2001Co-Authors: Akira J Ikushima, Hiroshi Kakiuchida, Kazuya SaitoAbstract:Recent studies on Silica Glass as a photonic material will be described. With regard to the structural disorder, investigations have been made to improve transparency and to shift the optical absorption edge in the ultraviolet towards shorter wavelengths. Remarkable advances have been achieved in the understanding of both light scattering, which is a dominant factor in the optical losses in Silica fibers, and the absorption edge. Freezing of the structural disorder was observed, and structural relaxations are found to be important for improving the transparency, whereas for the absorption edge thermal vibration effects seem to be more predominant than the structural disorder. From the results, the present authors have tried to control the structural relaxation for developing Silica Glass with an ultimate optical transparency, finding that a very tiny amount of the proper impurity species gives rise to structural subrelaxations, which are effective in reducing the Rayleigh scattering. The scattering was reduced by 13% by addition of only 10 wt.ppm Na 2 O, for example.
Bastian E. Rapp - One of the best experts on this subject based on the ideXlab platform.
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High-throughput thermal replication of transparent fused Silica Glass
Microfluidics BioMEMS and Medical Microsystems XVII, 2019Co-Authors: Frederik Kotz, Norbert Schneider, Andreas Striegel, Matthias Worgull, Bastian E. RappAbstract:Fused Silica Glass is the material of choice whenever high chemical and thermal resilience combined with high optical transparency is required. These properties make fused Silica Glass interesting in microfluidics for next generation chemical synthesis reactors as well as microoptics and photonics. However structuring of fused Silica Glass is difficult and upscaling of microfluidic concepts in Glass from laboratory scale prototypes to mass market manufacturing remains a problem. Polymers on the other hand remain the material of choice for low cost, disposable components in mass market manufacturing. We want to close the gap between the superior material properties of fused Silica and the ease of highthroughput polymer molding. Here we present high-throughput thermal replication of fused Silica Glass using thermal nanoimprinting and roll-to-roll replication. Therefore, thermoplastic nanocomposites are structured using classical polymer molding processes at moderate temperatures of 110°C and pressures of 27°MPa. Structuring can be done with submicron resolution and a surface roughness of a few nanometers. Roll-to-roll replication allows structuring these thermoplastic nanocomposites with speeds up to 5 m/min. The structured thermoplastic nanocomposites are then turned into fused Silica Glass in a final heat treatment.
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three dimensional printing of transparent fused Silica Glass
Nature, 2017Co-Authors: Frederik Kotz, Karl Arnold, Kai Sachsenheimer, Christiane Richter, Tobias M. Nargang, Nico Keller, Werner Bauer, Dorothea Helmer, Dieter Schild, Bastian E. RappAbstract:Using stereolithography 3D printers, a Silica nanocomposite is shaped and then fused to produce non-porous, very smooth, highly transparent fused Silica Glass components. Fused Silica Glass has long been known for its excellent optical properties, yet processing and patterning this material still requires high-temperature processes and/or hazardous chemical materials. To simplify such processes, Bastian Rapp and colleagues have been developing a system—termed 'liquid Glass'—in which a viscous amorphous Silica nanocomposite can be patterned into complex shapes by moulding and then photocured to produce optical-quality Glass structures. In their latest development, the group have tuned the properties of their nanocomposite to facilitate its use in a 3D printer, yielding high-optical-quality Glass structures with features as small as a few tens of micrometres. Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties1,2,3. However, Glasses and especially high-purity Glasses such as fused Silica Glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features3,4. These drawbacks have made Glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite5, here we create transparent fused Silica Glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable Silica nanocomposite that is 3D printed and converted to high-quality fused Silica Glass via heat treatment. The printed fused Silica Glass is non-porous, with the optical transparency of commercial fused Silica Glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured Glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused Silica Glass for many applications in both industry and academia.
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Three-dimensional printing of transparent fused Silica Glass
Nature, 2017Co-Authors: Frederik Kotz, Karl Arnold, Kai Sachsenheimer, Christiane Richter, Tobias M. Nargang, Nico Keller, Werner Bauer, Dorothea Helmer, Dieter Schild, Bastian E. RappAbstract:Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties1–3. However, Glasses and especially high-purity Glasses such as fused Silica Glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features3,4. These drawbacks have made Glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite5, here we create transparent fused Silica Glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable Silica nanocomposite that is 3D printed and converted to high-quality fused Silica Glass via heat treatment. The printed fused Silica Glass is non-porous, with the optical transparency of commercial fused Silica Glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured Glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused Silica Glass for many applications in both industry and academia.
Frederik Kotz - One of the best experts on this subject based on the ideXlab platform.
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High-throughput thermal replication of transparent fused Silica Glass
Microfluidics BioMEMS and Medical Microsystems XVII, 2019Co-Authors: Frederik Kotz, Norbert Schneider, Andreas Striegel, Matthias Worgull, Bastian E. RappAbstract:Fused Silica Glass is the material of choice whenever high chemical and thermal resilience combined with high optical transparency is required. These properties make fused Silica Glass interesting in microfluidics for next generation chemical synthesis reactors as well as microoptics and photonics. However structuring of fused Silica Glass is difficult and upscaling of microfluidic concepts in Glass from laboratory scale prototypes to mass market manufacturing remains a problem. Polymers on the other hand remain the material of choice for low cost, disposable components in mass market manufacturing. We want to close the gap between the superior material properties of fused Silica and the ease of highthroughput polymer molding. Here we present high-throughput thermal replication of fused Silica Glass using thermal nanoimprinting and roll-to-roll replication. Therefore, thermoplastic nanocomposites are structured using classical polymer molding processes at moderate temperatures of 110°C and pressures of 27°MPa. Structuring can be done with submicron resolution and a surface roughness of a few nanometers. Roll-to-roll replication allows structuring these thermoplastic nanocomposites with speeds up to 5 m/min. The structured thermoplastic nanocomposites are then turned into fused Silica Glass in a final heat treatment.
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Glassomer-Processing Fused Silica Glass Like a Polymer.
Advanced Materials, 2018Co-Authors: Frederik Kotz, Nico Keller, Werner Bauer, Dieter Schild, Norbert Schneider, Andreas Striegel, Andre Wolfschläger, Matthias Worgull, Marcel Milich, Christian GreinerAbstract:Fused Silica Glass is one of the most important high-performance materials for scientific research, industry, and society. However due to its high chemical and thermal resistance as well as high hardness, fused Silica Glass is notoriously difficult to structure. This work introduces Glassomer, a solid nanocomposite, which can be structured using polymer molding and subtractive technologies at submicrometer resolution. After polymer processing Glassomer is turned into optical grade fused Silica Glass during a final heat treatment. The resulting Glass has the same optical transparency as commercial fused Silica and a smooth surface with a roughness of a few nanometers. This work makes high-performance fused Silica Glass components accessible to high-throughput fabrication technologies and will enable numerous optical, photonic and medical applications in science and industry.
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three dimensional printing of transparent fused Silica Glass
Nature, 2017Co-Authors: Frederik Kotz, Karl Arnold, Kai Sachsenheimer, Christiane Richter, Tobias M. Nargang, Nico Keller, Werner Bauer, Dorothea Helmer, Dieter Schild, Bastian E. RappAbstract:Using stereolithography 3D printers, a Silica nanocomposite is shaped and then fused to produce non-porous, very smooth, highly transparent fused Silica Glass components. Fused Silica Glass has long been known for its excellent optical properties, yet processing and patterning this material still requires high-temperature processes and/or hazardous chemical materials. To simplify such processes, Bastian Rapp and colleagues have been developing a system—termed 'liquid Glass'—in which a viscous amorphous Silica nanocomposite can be patterned into complex shapes by moulding and then photocured to produce optical-quality Glass structures. In their latest development, the group have tuned the properties of their nanocomposite to facilitate its use in a 3D printer, yielding high-optical-quality Glass structures with features as small as a few tens of micrometres. Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties1,2,3. However, Glasses and especially high-purity Glasses such as fused Silica Glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features3,4. These drawbacks have made Glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite5, here we create transparent fused Silica Glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable Silica nanocomposite that is 3D printed and converted to high-quality fused Silica Glass via heat treatment. The printed fused Silica Glass is non-porous, with the optical transparency of commercial fused Silica Glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured Glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused Silica Glass for many applications in both industry and academia.
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Three-dimensional printing of transparent fused Silica Glass
Nature, 2017Co-Authors: Frederik Kotz, Karl Arnold, Kai Sachsenheimer, Christiane Richter, Tobias M. Nargang, Nico Keller, Werner Bauer, Dorothea Helmer, Dieter Schild, Bastian E. RappAbstract:Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties1–3. However, Glasses and especially high-purity Glasses such as fused Silica Glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features3,4. These drawbacks have made Glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite5, here we create transparent fused Silica Glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable Silica nanocomposite that is 3D printed and converted to high-quality fused Silica Glass via heat treatment. The printed fused Silica Glass is non-porous, with the optical transparency of commercial fused Silica Glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured Glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused Silica Glass for many applications in both industry and academia.
Dieter Schild - One of the best experts on this subject based on the ideXlab platform.
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Glassomer-Processing Fused Silica Glass Like a Polymer.
Advanced Materials, 2018Co-Authors: Frederik Kotz, Nico Keller, Werner Bauer, Dieter Schild, Norbert Schneider, Andreas Striegel, Andre Wolfschläger, Matthias Worgull, Marcel Milich, Christian GreinerAbstract:Fused Silica Glass is one of the most important high-performance materials for scientific research, industry, and society. However due to its high chemical and thermal resistance as well as high hardness, fused Silica Glass is notoriously difficult to structure. This work introduces Glassomer, a solid nanocomposite, which can be structured using polymer molding and subtractive technologies at submicrometer resolution. After polymer processing Glassomer is turned into optical grade fused Silica Glass during a final heat treatment. The resulting Glass has the same optical transparency as commercial fused Silica and a smooth surface with a roughness of a few nanometers. This work makes high-performance fused Silica Glass components accessible to high-throughput fabrication technologies and will enable numerous optical, photonic and medical applications in science and industry.
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three dimensional printing of transparent fused Silica Glass
Nature, 2017Co-Authors: Frederik Kotz, Karl Arnold, Kai Sachsenheimer, Christiane Richter, Tobias M. Nargang, Nico Keller, Werner Bauer, Dorothea Helmer, Dieter Schild, Bastian E. RappAbstract:Using stereolithography 3D printers, a Silica nanocomposite is shaped and then fused to produce non-porous, very smooth, highly transparent fused Silica Glass components. Fused Silica Glass has long been known for its excellent optical properties, yet processing and patterning this material still requires high-temperature processes and/or hazardous chemical materials. To simplify such processes, Bastian Rapp and colleagues have been developing a system—termed 'liquid Glass'—in which a viscous amorphous Silica nanocomposite can be patterned into complex shapes by moulding and then photocured to produce optical-quality Glass structures. In their latest development, the group have tuned the properties of their nanocomposite to facilitate its use in a 3D printer, yielding high-optical-quality Glass structures with features as small as a few tens of micrometres. Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties1,2,3. However, Glasses and especially high-purity Glasses such as fused Silica Glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features3,4. These drawbacks have made Glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite5, here we create transparent fused Silica Glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable Silica nanocomposite that is 3D printed and converted to high-quality fused Silica Glass via heat treatment. The printed fused Silica Glass is non-porous, with the optical transparency of commercial fused Silica Glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured Glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused Silica Glass for many applications in both industry and academia.
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Three-dimensional printing of transparent fused Silica Glass
Nature, 2017Co-Authors: Frederik Kotz, Karl Arnold, Kai Sachsenheimer, Christiane Richter, Tobias M. Nargang, Nico Keller, Werner Bauer, Dorothea Helmer, Dieter Schild, Bastian E. RappAbstract:Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties1–3. However, Glasses and especially high-purity Glasses such as fused Silica Glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features3,4. These drawbacks have made Glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite5, here we create transparent fused Silica Glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable Silica nanocomposite that is 3D printed and converted to high-quality fused Silica Glass via heat treatment. The printed fused Silica Glass is non-porous, with the optical transparency of commercial fused Silica Glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured Glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused Silica Glass for many applications in both industry and academia.