MBE growth of CeSi₂ thin films and their electrical transport properties

Epitaxial films of the dense Kondo compound CeSi₂(001) were successfully grown by depositing Ce onto a Si(001) surface with thickness ranging from 100 down to 5 Å. For the thick film with the Ce deposition of 100 Å, the electrical transport properties are the same as those of the bulk single crystal. It is found (i) that the coherent state of the heavy electrons maintains for the films with the Ce deposition of 30 Å or more, and (ii) that a hump with the peak position at 180 K is formed in the resistivity vs. temperature curve of the film with the Ce deposition of 60 Å or less and its relative height increases with decreasing film thickness indicating that the contribution of the magnetic scattering increases. These properties are discussed in terms of the quasi-two-dimensionality of the thin films.