Nigro Angela, Guarino Anita, Leo Antonio, Grimaldi Gaia, Avitabile Francesco, Romano Paola
Physics Department "E. R. Caianiello", University of Salerno, 84084 Fisciano (Salerno), Italy.
CNR-SPIN, c/o University of Salerno, 84084 Fisciano (Salerno), Italy.
Materials (Basel). 2023 Dec 14;16(24):7644. doi: 10.3390/ma16247644.
Point-contact spectroscopy was performed on bulk samples of electron-doped high temperature superconductor NdCeCuO. The samples were characterized using X-ray diffraction and scanning electron microscopy equipped with a wavelength-dispersive spectrometer and an electron backscatter diffraction detector. Samples with Ce content x = 0.15 showed the absence of spurious phases and randomly oriented grains, most of which had dimensions of approximately 220 µm. The low-bias spectra in the tunneling regime, i.e., high-transparency interface, exhibited a gap feature at about ±5 meV and no zero-bias conductance, despite the random oriented grains investigated within our bulk samples, consistent with most of the literature data on oriented samples. High-bias conductance was also measured in order to obtain information on the properties of the barrier. A V-shape was observed in some cases, instead of the parabolic behavior expected for tunnel junctions.
对电子掺杂高温超导体NdCeCuO的块状样品进行了点接触光谱分析。使用配备波长色散光谱仪和电子背散射衍射探测器的X射线衍射和扫描电子显微镜对样品进行了表征。Ce含量x = 0.15的样品显示不存在杂相且晶粒随机取向，其中大多数晶粒尺寸约为220 µm。在隧穿 regime （即高透明度界面）下的低偏置光谱在约±5 meV处呈现出能隙特征且无零偏置电导，尽管我们对块状样品中随机取向的晶粒进行了研究，但这与大多数关于取向样品的文献数据一致。还测量了高偏置电导以获取有关势垒特性的信息。在某些情况下观察到了V形，而不是隧道结预期的抛物线行为。
