Temperature-invariant valence-band 4f photoemission features in the heavy-fermion compound YbAl3.
Temperature-invariant valence-band 4f photoemission features in the heavy-fermion compound YbAl3.
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重费米子化合物 YbAl3 中的温度不变价带 4f 光电发射特征。
DOI：
10.1103/physrevb.48.9497
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Lawrence
中科院分区：
文献类型：
--
作者：
Blyth;Joyce;Arko;Canfield;Andrews;Fisk;Thompson;Bartlett;Riseborough;Tang;Lawrence
对重费米子化合物YbAl3进行了高分辨率光电发射（PES）研究，以测试单杂质模型的定性和定量预测。YbAgCu4和YbCu2Si2的数据也得到了证实。对于基于镱的重费米子，该模型预测了一个完全占据的近藤共振，因此它的宽度、强度和温度依赖关系应该可以通过PES直接获得。由于存在温度和/或污染相关的表面特征，这些特征没有被模型处理，因此需要严格的归一化和曲线拟合程序来提取总体4f线形状。对于我们采用的特殊温度循环方法，我们没有观察到之前被确定为近藤共振的峰值有任何温度依赖性。我们发现该峰的结合能和宽度都明显大于理论预测。YbAl3和LuAl3之间4f线形状和表面位移的变化趋势与元素Yb和Lu之间4f核水平的变化趋势一致。在YbCu2Si2和YbAgCu4中也发现了类似的循环方法。最近对这些系统中温度依赖性的观测最容易从表面现象来理解。©1993美国物理学会。
A high-resolution photoemission (PES) study of the heavy-fermion compound YbAl3 has been undertaken to test the qualitative and quantitative predictions of the single-impurity model. Corroborating data on YbAgCu4 and YbCu2Si2 are also presented. For Yb-based heavy fermions the model predicts a fully occupied Kondo resonance so that its width, intensity, and temperature dependence should be directly accessible by PES. Due to the existence of temperature- and/or contamination-dependent surface features, which are not dealt with by the model, a rigorous normalization and curve-fitting procedure was required to extract the bulk 4f line shape. For the particular temperature cycling method employed by us, we do not observe any temperature dependence in the peak that had been previously identified as the Kondo resonance. We find that both the binding energy and width of this peak are significantly larger than theory predicts. It is also found that the trends in 4f line shape and surface shift between YbAl3 and LuAl3 are consistent with the trends seen between the 4f core levels of elemental Yb and Lu. Similar results are also found in YbCu2Si2 and YbAgCu4 for similar cycling methods. Recent observations of temperature dependence in these systems are most easily understood in terms of surface phenomena. © 1993 The American Physical Society.