| Item type |
デフォルトアイテムタイプ_（フル）(1) |
| 公開日 |
2023-03-18 |
| タイトル |
|
|
タイトル |
Off-center rattling and thermoelectric properties of type-II clathrate (K, Ba)(24)(Ga, Sn, square)(136) single crystals |
|
言語 |
en |
| 作成者 |
Mano, Satomi
Onimaru, Takahiro
Yamanaka, Shoji
Takabatake, Toshiro
|
| アクセス権 |
|
|
アクセス権 |
open access |
|
アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 権利情報 |
|
|
権利情報 |
(c) 2011 American Physical Society |
| 主題 |
|
|
主題Scheme |
NDC |
|
主題 |
420 |
| 内容記述 |
|
|
内容記述 |
We report the synthesis and temperature-dependent structural, transport, and thermal properties of type-II clathrate K8+xBa16-xGa40-ySn96-z square(y+z) (1.2 <= x <= 2.8, 2.0 <= y <= 3.3, 0.8 <= z <= 6.6, square = framework vacancy). Single-crystal x-ray diffraction analysis reveals that the guest K+ and Ba2+ ions are preferentially incorporated into the hexakaidecahedral cages and dodecahedral cages, respectively. The guest site in the former splits into four sites 0.67 angstrom away from the center to the 32e site of the cage. The splitting is consistent with the presence of four minima in the electrostatic potential in the hexakaidecahedron. The thermopower is negative and relatively large, -50 similar to -120 mu V/K at 300 K, indicating that the dominant charge carriers are electrons. The thermal conductivity displays a glasslike behavior with a plateau at around 20 K. The analysis of the specific heat indicates that the motion of the K+ ion in the hexakaidecahedron can be described by the soft-potential model, including the tunneling term. The characteristic energy of 21 K for the soft mode is as low as that of the off-center rattling of the Ba2+ ion in type-I clathrate Ba8Ga16Sn30. The present result on the type-II clathrate verifies the idea that the low-energy off-center rattling in oversized cages of intermetallic clathrates couples to the acoustic phonons to lead to the glasslike thermal conductivity. |
|
言語 |
en |
| 出版者 |
|
|
出版者 |
American Physical Society |
| 言語 |
|
|
言語 |
eng |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
|
資源タイプ |
journal article |
| 出版タイプ |
|
|
出版タイプ |
VoR |
|
出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| 関連情報 |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
10.1103/PhysRevB.84.214101 |
| 関連情報 |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
http://dx.doi.org/10.1103/PhysRevB.84.214101 |
| 収録物識別子 |
|
|
収録物識別子タイプ |
ISSN |
|
収録物識別子 |
1098-0121 |
| 収録物識別子 |
|
|
収録物識別子タイプ |
NCID |
|
収録物識別子 |
AA11187113 |
| 開始ページ |
|
|
開始ページ |
214101 |
| 書誌情報 |
Physical Review B
Physical Review B
巻 84,
号 21,
p. 214101,
発行日 2011
|
| 旧ID |
34744 |
PhysRevB_84_214101.pdf (895.2 KB)
