Kohn anomaly in MgB2 by inelastic X-ray scattering.
Kohn anomaly in MgB2 by inelastic X-ray scattering.
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DOI：
10.1103/physrevlett.92.197004
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发表时间：
2003-09
影响因子：
8.6
通讯作者：
A. Baron;H. Uchiyama;Y. Tanaka;S. Tsutsui;D. Ishikawa;S. Lee;R. Heid;K. Bohnen;S. Tajima;T. Ishikawa
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文献类型：
--
作者：
A. Baron;H. Uchiyama;Y. Tanaka;S. Tsutsui;D. Ishikawa;S. Lee;R. Heid;K. Bohnen;S. Tajima;T. Ishikawa
我们研究声子在MgB2使用非弹性X射线散射（1.6和6毫电子伏的分辨率）。我们清楚地观察到软化和扩大的关键E（2g）模式通过科恩异常沿着伽玛M，在良好的协议与从头计算。低温测量（略高于和低于T（c））显示，所研究的动量传递变化可以忽略不计，并且在室温和16 K之间A处E（2g）模式没有变化。我们报告的存在下，纵向模式沿着GammaA附近的能量的E（2g）模式，这是没有预测的理论。
We study phonons in MgB2 using inelastic x-ray scattering (1.6 and 6 meV resolution). We clearly observe the softening and broadening of the crucial E(2g) mode through the Kohn anomaly along GammaM, in excellent agreement with ab initio calculations. Low temperature measurements (just above and below T(c)) show negligible changes for the momentum transfers investigated and no change in the E(2g) mode at A between room temperature and 16 K. We report the presence of a longitudinal mode along GammaA near in energy to the E(2g) mode that is not predicted by theory.