Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method
Lanthanoid silicates (Ln9.33Si6O26) adopt the hexagonal apatite structure and show potential as solid oxide fuel cell (SOFC) electrolytes due to their high oxide ion conductivity at intermediate temperatures (500–700 °C). Ions migrate preferentially along the crystallographic c-axis, and can be impr...
| Main Authors: | , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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2017
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| Online Access: | https://hdl.handle.net/10356/85586 http://hdl.handle.net/10220/43747 |
| _version_ | 1826129215172378624 |
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| author | An, Tao Baikie, Tom Wei, Fengxia Li, Henan Brink, Frank Wei, Jun Ngoh, Shwu Lan White, Timothy John Kloc, Christian |
| author2 | School of Materials Science & Engineering |
| author_facet | School of Materials Science & Engineering An, Tao Baikie, Tom Wei, Fengxia Li, Henan Brink, Frank Wei, Jun Ngoh, Shwu Lan White, Timothy John Kloc, Christian |
| author_sort | An, Tao |
| collection | NTU |
| description | Lanthanoid silicates (Ln9.33Si6O26) adopt the hexagonal apatite structure and show potential as solid oxide fuel cell (SOFC) electrolytes due to their high oxide ion conductivity at intermediate temperatures (500–700 °C). Ions migrate preferentially along the crystallographic c-axis, and can be improved by introducing lower valent elements at the silicon sites. To better understand this phenomenon, single crystals of aluminium-doped neodymium silicate Nd9.33+x/3AlxSi6−xO26 (0≤x≤1) were synthesised using the floating-zone method in an inert environment at a growth rate of 5 mm/L. The products with x<1.5 were homogeneous, transparent and crack-free crystals. For x=1.5 the monophasic crystal contained minor cracks after cooling and for x=2 a two phase (apatite+NdAlO3) polycrystalline mass was obtained. The quality of the 0≤x≤1.5 crystals were confirmed by neutron diffraction and synchrotron X-ray rocking curve diffraction. The incorporation of aluminium into apatite at nominal concentrations was independently established by energy dispersive X-ray spectroscopy (EDX), and electron backscatter diffraction (EBSD) found the crystallographic habit showed extension along [001]. |
| first_indexed | 2024-10-01T07:37:02Z |
| format | Journal Article |
| id | ntu-10356/85586 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:37:02Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | ntu-10356/855862020-09-26T22:11:25Z Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method An, Tao Baikie, Tom Wei, Fengxia Li, Henan Brink, Frank Wei, Jun Ngoh, Shwu Lan White, Timothy John Kloc, Christian School of Materials Science & Engineering A*STAR SIMTech Crystal structure Floating zone technique Lanthanoid silicates (Ln9.33Si6O26) adopt the hexagonal apatite structure and show potential as solid oxide fuel cell (SOFC) electrolytes due to their high oxide ion conductivity at intermediate temperatures (500–700 °C). Ions migrate preferentially along the crystallographic c-axis, and can be improved by introducing lower valent elements at the silicon sites. To better understand this phenomenon, single crystals of aluminium-doped neodymium silicate Nd9.33+x/3AlxSi6−xO26 (0≤x≤1) were synthesised using the floating-zone method in an inert environment at a growth rate of 5 mm/L. The products with x<1.5 were homogeneous, transparent and crack-free crystals. For x=1.5 the monophasic crystal contained minor cracks after cooling and for x=2 a two phase (apatite+NdAlO3) polycrystalline mass was obtained. The quality of the 0≤x≤1.5 crystals were confirmed by neutron diffraction and synchrotron X-ray rocking curve diffraction. The incorporation of aluminium into apatite at nominal concentrations was independently established by energy dispersive X-ray spectroscopy (EDX), and electron backscatter diffraction (EBSD) found the crystallographic habit showed extension along [001]. ASTAR (Agency for Sci., Tech. and Research, S’pore) MOE (Min. of Education, S’pore) Accepted version 2017-09-15T08:27:26Z 2019-12-06T16:06:37Z 2017-09-15T08:27:26Z 2019-12-06T16:06:37Z 2011 Journal Article An, T., Baikie, T., Wei, F., Li, H., Brink, F., Wei, J., et al. (2011). Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method. Journal of Crystal Growth, 333(1), 70-73. 0022-0248 https://hdl.handle.net/10356/85586 http://hdl.handle.net/10220/43747 10.1016/j.jcrysgro.2011.08.010 en Journal of Crystal Growth © 2011 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of Crystal Growth, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.jcrysgro.2011.08.010]. 16 p. application/pdf |
| spellingShingle | Crystal structure Floating zone technique An, Tao Baikie, Tom Wei, Fengxia Li, Henan Brink, Frank Wei, Jun Ngoh, Shwu Lan White, Timothy John Kloc, Christian Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method |
| title | Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method |
| title_full | Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method |
| title_fullStr | Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method |
| title_full_unstemmed | Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method |
| title_short | Single crystal growth of apatite-type Al-doped neodymium silicates by the floating zone method |
| title_sort | single crystal growth of apatite type al doped neodymium silicates by the floating zone method |
| topic | Crystal structure Floating zone technique |
| url | https://hdl.handle.net/10356/85586 http://hdl.handle.net/10220/43747 |
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