2006 Fiscal Year Final Research Report Summary
Electrical anomalies and the localized to delocalized transition for lanthanide pnictides at high pressures
| Project/Area Number |
17540310
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Muroran Institute of Technology |
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Principal Investigator |
SHIROTANI Ichimin Muroran Institute of Technology, Department of Engineering, Prof., 工学部, 特任教授 (90110692)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEDA Keiki Muroran Institute of Technology, Department of Engineering, Research Associate, 工学部, 助手 (70352060)
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| Project Period (FY) |
2005 – 2006
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| Keywords | High pressure / Phase transition / X-ray diffraction / Synchrotron radiation / Lanthanide pnictides / Crystal structure / Bulk modulus |
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| Research Abstract |
By use of synchrotron radiation, powder x-ray diffraction of LnBi (Ln = La, Nd, Sm, Gd, Tb, Ho and Tm) with a NaCl-type structure has been studied up to 35 GPa at room temperature. The detailed pressure-volume relationship for SmBi is obtained. The isostructural phase transition reported by Benedict et al. is not found at around 2.6 GPa. However, we have observed a first-order phase transition for SmBi at around 18 GPa. SmBi transforms from the NaCI-type to a tetragonal (distorted CsCl-type) structure with the volume collapse of about 8.2 % at around 18 GPa. Crystal data of the high-pressure phase of SmBi are a = 3.775(5) Å, c = 3.25 (2) Å, c/a = 0.86 and V = 46.4 (3) Å^3 at 20.3 GPa. The structure of SmBi at high pressure is isostructural with that of SmAs. A bulk modulus of SmBi is obtained from the volume vs. pressure curve fitted by a Birch equation of state. The bulk modulus and its pressure derivative of this compound are B_0 = 67 ± 2 GPa, B_0' = 2.6 ± 0.3. We have found also the structural phase transitions for LnBi (Ln = La, Nd, Sm, Gd, Tb, Ho and Tm) at high pressures.
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Research Products
(12 results)
