【摘要】 利用铍过滤探测器中子谱仪分别在298K及87K测量了Y-Ba-Cu-O超导体(T_c=90.5K)的广义声子谱。87K时,在76meV处观察到一个光学模,估计为Cu-O-Cu的伸张模,同时在6meV以下出现较强的声学模。而289K时在10meV及19meV观察到的低频模在87K时不再出现,很可能是被软化了。上述声子谱的异常变化可能与Y-Ba-Cu—O的较高的超导转变温度密切相关。更多还原

【Abstract】 The generalized phonon density of states of Y-Ba-Cu-0 superconductor (TC = 90.5K) have been measured at 289 K and 87 K respectively, by using Be filter detector neutron inelastic scattering spectrometer at Institute of Atomic Energy. At 87 K, the optical mode at 76 meV which is estimated owing to Cu-O-Cu breathing mode and a stronger acoustic mode below 6 meV" are observed, and the low frequency modes at 10 meV and 19 meV in 289 K seems to be disappeared, or to be softened. It is possible that the anomalous change of phonon density of states below Tc is responsible for the higher superconducting transition temperature of Y-Ba-Cu-O.更多还原