Topic:
Zigzag and rectangular linear structures composed of adsorbed oxygen atoms on surfaces of SrRuO3 thin films. The images were obtained in-situ with a Scanning Tunneling Microscope.
Atomically resolved imaging of the SrRuO3 surface and ab-initio modeling reveal a link between patterns of adsorbed oxygen atoms and the electronic and magnetic properties of the topmost atomic layer with frustrated spins of adsorbed oxygens. Because this perovskite is commonly used as an electrode layer in epitaxial heterostructures, understanding its surface is critically important for understanding thin film growth and properties of epitaxial systems in the ultrathin limit. The reported atomic-scale, in-situ imaging of epitaxially grown SrRuO3 and the subsequent ex-situ analysis show that structures on the SrRuO3 film surfaces depend on film growth conditions and are dominated by patterns formed by adsorbed oxygen atoms. Ab-initio modeling suggests that local electronic and magnetic properties of the SrRuO3 surfaces are determined by the chemical composition of the topmost layer. In particular, it is predicted that the layers of adsorbed oxygen atoms is magnetic at low temperatures, with a magnetic behavior reminiscent of spin glass. In turn, the pristine SrO-terminated surface is half-metallic, which is of a strong interest for realization of spintronic devices.
For more information, please contact Sergei Kalinin, sergei2@ornl.gov.
A. Tselev, P. Ganesh, L. Qiao, W. Siemons, Z. Gai, M. D. Biegalski, A. P. Baddorf, and S. V. Kalinin, “Oxygen control of atomic structure and physical properties of SrRuO3 surfaces,” ACS Nano (2013), DOI: 10.1021/nn400923n.