2017 Fiscal Year Final Research Report
Valence fluctuation in rare-earth 4f electrons and giant negative thermal expansion
| Project/Area Number |
16K13663
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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 |
Applied 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 – 2018-03-31
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| Keywords | 応用物性 / 無機材料 / 負熱膨張 / アクチュエータ |
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| Outline of Final Research Achievements |
We achieved giant isotropic negative thermal expansion (NTE) with volume change up to 3.4%, via control of the electronic configuration in Sm atoms of SmS, (4f)6 or (4f)5(5d)1, by partial replacement of Sm with Y. The present total volume change related to NTE is the largest among isotropic NTE materials. Isotropic NTE has a great merit from the viewpoint of engineering, because it can avoid strains or defects and, therefore, the NTE function is stable against repeated thermal cycling. Volume control of lanthanide monosulfides via tuning of the 4f electronic configuration provides us with a new avenue for volume control of a material.
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| Free Research Field |
固体物理学
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