N. Moslemzadeh

Growth characteristics of dysprosium on tungsten surfaces

Abstract Using Dy 3d 3/2 XPS intensities and LEED, growth mode and film morphology of Dy on W(110) and W(100) were investigated. A laminar growth with well ordered film morphology was found for Dy on W(110). The growth of Dy on W(100) followed the Stranski–Krastanov mode. While no ordered structure was found for growth at RT growth, the epitaxial relations of Dy(0001)‖W(100) and Dy[1120]‖W[010] were observed for growth at 470 K.

Electronic changes of dysprosium and tungsten during growth of Dy on W(100)

Abstract Dy growth on W(100) has been studied with W 4f 7/2 core-level shift (CLS) and Dy/W(100) valence band analysis. CLS measurements of the W 4f 7/2 peaks during the growth resulted in three Dy-induced features at 31.24±0.02, 30.92±0.02 and 30.74±0.02 eV binding energies. The shift in the W 4f 7/2 peak is consistent with the reconstruction seen in the Dy thin film. Valence band study of Dy/W(100) showed an interfacial hybridization between Dy and W(100) which may be responsible for the high thermal stability of Dy superstructures on W(100). The same direction of shift in Dy 4f levels and the W 4f 7/2 level during growth suggest that these shifts are mainly strain dependent. Increasing the Dy overlayer thickness to more than 2 ML resulted in Dy 5d–6s hybridization which has been attributed to the formation of islands of Dy.