【摘要】 在超高真空系统中制备了C6 0 的Yb填隙化合物薄膜 .用x射线光电子能谱研究了Yb和C6 0 结合过程中C 1s ,Yb4f和Yb 4d的变化 .利用Yb 4f和C 1s的谱峰强度确定出相纯样品的化学组分接近Yb2 .75C6 0 ,这一结果与晶体x射线衍射结果一致 .Yb 4f和Yb 4d的峰形与峰位表明化合物中Yb的价态为Yb2 + .相纯样品 (Yb2 .75C6 0 )的C 1s峰位相对于纯C6 0 向低结合能方向移动约 0 .5eV .C 1s结合能减小说明有Yb 6s电子转移到C6 0 的最低未充填分子轨道能带上 .结合能变化大小及峰宽的具体数值为进一步在薄膜样品上研究Yb2 .75C6 0 提供了表征样品的手段更多还原

【Abstract】 Yb-intercalated C 60 thin film was prepared in a ultra-high-vacuum system. The binding energies of C 1s, Yb 4f and Yb 4d during the compound formation were studied by x-ray photoemission technique. The stoichiometry of the phase-pure sample was determined by the peak intensities of Yb 4f and C 1s. The result turned to be very near to that for Yb 2.75C 60 that was first determined for bulk-phase sample by x-ray diffraction measurement. The positions and intensities of the Yb 4f and Yb 4d peaks revealed the charge state of Yb 2+ in Yb 2.75C 60. The C 1s core level for the phase-pure sample shifted towards lower binding energy by ≈0.5 eV relative to C 60, which exhibited that some Yb 6s electrons transferred from Yb to the lowest unoccupied molecular orbital band of C 60. The shift and the FWHM of C 1s x-ray photoemission spectroscopic peak can be used as sample characterization in future researches on Yb/C 60 compounds.更多还原