Spin resolved resonant inverse photoemission

在这一年里，我们制作了自旋分辨电子g^&lt；uc&gt；G^&lt；Un&gt；的电子源是由Cs包覆的GaAsP制成的，其中Cs降低了功函数。这是NEA阴极型。实验是在我们自制的SXES光谱仪上进行的。Ce 4d吸收边附近的Ripes测量揭示了CePd_7体态和表面态的显著对比电子结构。Ce 4d*4f边的Ripes是研究表面4f态的有力手段。主体是类似阿尔法的，表面是类似伽马的。体相和表面基态组态的不同反映了不同的共振。体相极高的Kondo温度(KT_K-0.95 eV)表明4f电子与配基电子之间有很强的杂化作用。我们的结果与计算结果是一致的。由于Ce-Ce间距很大，在IAM框架内的计算似乎给出了很好的一致。4f截面的共振增强使得区分费米能级附近光谱的具体贡献成为可能。指出Ce-4d边缘附近的Ripes测量对表面具有很高的灵敏度。此外，能带方案(LMTO)与主要来源于Ce-5d的离共振谱有很好的一致性。然而，能带计算低估了Ce 5d组分在费米能级以上的能量位置约1.4 eV。

In this year, we made spin resolved electron g^<uc>. The electron source of the g^<un> is made by Cs coated GaAsP, where Cs decreases the work function. This is NEA cathod type.The experiments were carried Out by the SXES spectrometer that was made by us. The RIPES measurement near Ce 4d absorption edge reveals the remarkable contrastive electronic structure at the bulk and surface state of CePd_7. The RIPES at Ce 4d * 4f edge is found to be a powerful method to investigate the surface 4f state. The bulk is alpha-like and the surface is gamma-like. The difference of the ground state configuration at the bulk and surface reflects the separate resonances. The extremely high Kondo temperature (kT_K-O.95 eV) of bulk expresses the very strong hybridization between the 4f and ligand electrons. Our results are consistent with the calculated results. Due to the large Ce-Ce spacing, the calculation within the framework of IAM seems to give a good agreement. The resonant enhancement of 4f-cross section makes it possible to distinguish between the specific contributions in the spectra near Fermi level. It is pointed out that the RIPES measurement around Ce 4d edge has high sensitivity to the surface. Also, the energy band scheme (LMTO) gives a qualitatively good agreement with the off resonance spectra, which are mainly of Ce 5d origin. However, band calculation underestimates the energy position of the Ce 5d component above the Fermi level by about 1.4 eV.