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Transparent polycrystalline nanoceramics consisting of triclinic Al2SiO5 kyanite and Al2O3 corundum |
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| Authors: | Nico A Gaida Norimasa Nishiyama Atsunobu Masuno Ulrich Schürmann Christopher Giehl Oliver Beermann Hiroaki Ohfuji Jozef Bednarcik Eleonora Kulik Astrid Holzheid Tetsuo Irifune Lorenz Kienle |
| Affiliation: | 1. Institute for Materials Science, Kiel University, Kiel, Germany;2. Institute of Geosciences, Kiel University, Kiel, Germany;3. Deutsches Elektronen‐Synchrotron DESY, Hamburg, Germany;4. Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, Japan;5. Institute of Industrial Science, The University of Tokyo, Tokyo, Japan;6. Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan;7. Geodynamics Research Center, Ehime University, Matsuyama, Japan;8. Bayerisches Geoinstitut, University Bayreuth, Bayreuth, Germany;9. Earth‐Life Science Institute, Tokyo Institute of Technology, Ookayama, Tokyo, Japan |
| Abstract: | Transparent polycrystalline nanoceramics consisting of triclinic Al2SiO5 kyanite (91.4 vol%) and Al2O3 corundum (8.6 vol%) were fabricated at 10 GPa and 1200‐1400°C. These materials were obtained by direct conversion from Al2O3‐SiO2 glasses fabricated using the aerodynamic levitation technique. The material obtained at 10 GPa and 1200°C shows the highest optical transparency with a real in‐line transmission value of 78% at a wavelength of 645 nm and a sample‐thickness of 0.8 mm. This sample shows equigranular texture with an average grain size of 34 ± 13 nm. The optical transparency increases with decreasing mean grain size of the constituent phases. The relationship between real in‐line transmission and grain size is well explained by a grain‐boundary scattering model based on a classical theory. |
| Keywords: | alumina aluminosilicates nanocomposites transparent ceramics |