We have studied the electronic structure of the d-electron heavy-fermion system CaCu 3 Ru 4 O 12 using x-ray photoemission spectroscopy and a cluster model calculation. The Ru 3d core level spectrum shows a doublepeak structure as commonly observed in metallic Ru oxides. In CaCu 3 Ru 4 O 12 , the well-screened peak has dominating intensity, indicating that the Ru 4d electrons in CaCu 3 Ru 4 O 12 are highly itinerant. On the other hand, the Cu 2p 3/2 core level peak is accompanied by a satellite and shows that the valence state of Cu is close to 3d 9 ͑Cu 2+ ͒ with localized character. In addition, the main Cu 2p 3/2 peak shows an asymmetric line shape due to the screening effect, suggesting the hybridization effect between the Cu 3d and Ru 4d orbitals. The present results show that, among the d-electron heavy-fermion materials, the electronic structure of CaCu 3 Ru 4 O 12 best resembles that of the f-electron Kondo system.

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High-energy ion scattering ͑HEIS͒, x-ray photoelectron spectroscopy, and x-ray photoelectron diffraction ͑XPD͒ were used to study the growth of thin Ti films on Al͑001͒ surfaces. The Al surface peak area in the backscattered ion spectrum of MeV He ϩ ions, incident along the ͓001͔ direction, was used to monitor the atomic structure of the Ti films during growth. An initial decrease in the area was observed indicating epitaxial film growth. This decrease continued up to a critical film thickness of about 5.5 ML, after which point the structure of the film changed. Titanium films 3, 5, and 9 ML thick were characterized using XPD in the same chamber. Both the HEIS and XPD results show that the Ti films grow with an fcc structure on Al͑001͒. A tetragonal distortion of 2.4% in the fcc Ti film was measured using ions incident along the ͓101͔ direction. Although there is a general similarity of fcc Ti growth on both Al͑001͒ and Al͑110͒, the submonolayer growth regime does show differences for the two surfaces.