Thickness Dependence of Electronic and Magnetic Properties of
Ultrathin SrRuO3 Film
Choong H. Kim1 and Jaejun Yu 1, 2
1
Department of Physics and Astronomy and Center for Strongly Correlated
Materials Research, Seoul National University, Seoul 151-747, Korea
2
Center for Theoretical Physics, Seoul National University, Seoul 151-747, Korea
The electronic and magnetic properties of the ultrathin SrRuO$_{3}$ films have attracted a
good interest due to its use as a metallic substrate for the epitaxial growth of various perovskite
oxide superlattices. While the bulk SrRuO$_{3}$ is well known to have a metallic
ferromagnetic ground state, its surface electronic structure remains controversial as to possible
changes of magnetic characteristics and metal-insulator transitions as well. We carried out firstprinciples local density functional calculations to investigate the electronic and magnetic
properties of the ultrathin SrRuO$_{3}$ films as a function of its thickness. We used the slab
geometry for the calculations of SrRuO$_{3}$ layers over the SrTiO$_{3}$ (001) substrate.
From the results, it is found that the metallic ground state remains robust even in the singlelayer limit in contrast to the previous photoemission spectroscopy measurement. On the other
hand, the ferromagnetic moments become significantly suppressed at the interface and surface
layers of SrRuO$_{3}$. The thickness dependence of ferromagnetism could be understood in
terms of a quantum confinement effect.