2016 Fiscal Year Final Research Report
Enhancement of room-temperature ductility of ceramic single crystals
| Project/Area Number |
16K14414
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Structural/Functional materials
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2017-03-31
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| Keywords | 格子欠陥 / 結晶塑性 / 低温脆性 / セラミックス / 電子構造制御 |
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| Outline of Final Research Achievements |
Most ceramics are brittle at room temperatures. This is believed to be because large translation vectors in crystal structures leads to the large Burgers vector of dislocations, resulting in the large Peierls stress. In contrast, strontium titanate single (SrTiO3) crystals exhibit ductility even at room temperature if they are deformed at slow strain-rate although SrTiO3 is a ceramic with the large translation vector. In this study, therefore, uniaxial deformation tests were conducted for SrTiO3 single crystals with different chemical compositions, in order to reveal the influence of point defects on room-temperature plastic deformation of SrTiO3. It was found that SrTiO3 single crystals grown from the powder with a particular Sr/Ti ratio exhibited lower deformation stress and larger failure strain, as compared to SrTiO3 crystals with the other ratio. It is remarkable that room-temperature ductility of ceramic crystals is dependent on the introduced point defects.
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| Free Research Field |
結晶格子欠陥
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