Structural analysis of the intermetallic surface compound CePt5/Pt(lll).
- Resource Type
- Article
- Authors
- Kemmer, Jeannette; Praetorius, Christian; Krönlein, Andreas; Pin-Jui Hsu; Kai Fauth; Bode, Matthias
- Source
- Physical Review B: Condensed Matter & Materials Physics. Nov2014, Vol. 90 Issue 19, p195401-1-195401-10. 10p.
- Subject
- *SCANNING tunneling microscopy
*DIFFRACTION patterns
*LOW temperatures
*FOURIER transforms
*METALLIC films
- Language
- ISSN
- 1098-0121
We report on a detailed low-energy electron diffraction (LEED) and low-temperature scanning tunneling microscopy (STM) study of the intermetallic surface compound CePt5 on Pt(l 11). Depending on the thickness we observe various diffraction patterns and superstructures. In the low-thickness regime a slightly compressed (2 × 2) superstructure is aligned along the ‹110› direction of the Pt(lll) substrate. STM reveals another, much larger superstructure with a periodicity of (9.02 ± 0.45) nm presumably responsible for the strongly broadened T FED spots. At about 3 unit cells (u.c.) the surface is dominated by a (3√3 × 3√3)R30° pattern as revealed by T FED satellites and Fourier-transformed high-resolution STM images. It is interpreted as a moire pattern between the film and the substrate. We precisely determine the superstructure of the intermetallic film to (10/9√3 × 10/9 √3)R30° with respect to the Pt(111) substrate. Above 3 u.c. the satellites progressively disappear. A model is developed that consistently describes this thickness-dependent transition. For CePt5 films with a thickness between 6 and 11 u.c. the lattice of the compressed (2 × 2) superstructure rotates back into the substrate's ‹110› directions. [ABSTRACT FROM AUTHOR]