Neutron and nuclear inelastic scattering study of the Einstein oscillators in Ba-, Sr-, and Eu-filled germanium clathrates -: art. no. 174301

被引:59
作者
Hermann, RP
Schweika, W
Leupold, O
Rüffer, R
Nolas, GS
Grandjean, F
Long, GJ
机构
[1] Univ Liege, Dept Phys, B-4000 Sart Tilman Par Liege, Belgium
[2] Forschungszentrum Julich GmbH, Inst Festkorperforsch, D-52425 Julich, Germany
[3] European Synchrotron Radiat Facil, F-38043 Grenoble, France
[4] Univ S Florida, Dept Phys, Tampa, FL 33620 USA
[5] Univ Missouri, Dept Chem, Rolla, MO 65409 USA
来源
PHYSICAL REVIEW B | 2005年 / 72卷 / 17期
关键词
D O I
10.1103/PhysRevB.72.174301
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Inelastic neutron scattering measurements on Ba8Ga16Ge30 and Sr8Ga16Ge30 indicate the presence of soft local modes with Einstein oscillator energies of 4.9 +/- 0.1 and 4.4 +/- 0.1 meV, modes which are associated with the lowest "rattling" mode of the Ba(B) and Sr(B) guests, respectively. Nuclear inelastic scattering measurements on Eu8Ga16Ge30 yield Einstein oscillator energies of between 3.0 +/- 0.3 and 7.5 +/- 1.2 meV for the different modes of the Eu guests. Further, the resonant character of the measurements on Eu8Ga16Ge30 reveals, without question, that neither of the Eu guests exhibit any vibrational modes above 9 meV.
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页数:6
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