Glasslike versus crystalline thermal conductivity in carrier-tuned Ba8 Ga16 X30 clathrates (X=Ge,Sn)
Physical Review B - Condensed Matter and Materials Physics Volume 74 Issue 12
Page 125109-
published_at 2006-09
アクセス数 : 943 件
ダウンロード数 : 230 件
今月のアクセス数 : 2 件
今月のダウンロード数 : 0 件
この文献の参照には次のURLをご利用ください : https://ir.lib.hiroshima-u.ac.jp/00016645
File |
PhysRevB_74_125109.pdf
414 KB
種類 :
fulltext
|
Title ( eng ) |
Glasslike versus crystalline thermal conductivity in carrier-tuned Ba8 Ga16 X30 clathrates (X=Ge,Sn)
|
Creator |
Avila M. A.
|
Source Title |
Physical Review B - Condensed Matter and Materials Physics
|
Volume | 74 |
Issue | 12 |
Start Page | 125109 |
Abstract |
The present controversy over the origin of glasslike thermal conductivity observed in certain crystalline materials is addressed by studies on single-crystal x-ray diffraction, thermal conductivity κ (T), and specific heat Cp (T) of carrier-tuned Ba8 Ga16 X30 (X=Ge,Sn) clathrates. These crystals show radically different low-temperature κ (T) behaviors depending on whether their charge carriers are electrons or holes, displaying the usual crystalline peak in the former case and an anomalous glasslike plateau in the latter. In contrast, Cp (T) above 4 K and the general structural properties are essentially insensitive to carrier tuning. We analyze these combined results within the framework of tunneling scattering, resonant scattering, and Rayleigh scattering models, and conclude that the evolution from crystalline to glasslike κ (T) is accompanied by an increase both in the effective density of tunneling states and in the resonant scattering level, while neither one of these contributions can solely account for the observed changes in the full temperature range. This suggests that the most relevant factor that determines crystalline or glasslike behavior is the coupling strength between the guest vibrational modes and the frameworks with different charge carriers.
|
NDC |
Physics [ 420 ]
|
Language |
eng
|
Resource Type | journal article |
Publisher |
American Physical Society
|
Date of Issued | 2006-09 |
Rights |
Copyright (c) 2006 American Physical Society
|
Publish Type | Version of Record |
Access Rights | open access |
Source Identifier |
[NCID] AA11187113
[ISSN] 1098-0121
[DOI] 10.1103/PhysRevB.74.125109
[DOI] http://dx.doi.org/10.1103/PhysRevB.74.125109
|