Berlin 2012 – scientific programme
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O: Fachverband Oberflächenphysik
O 43: Clean surfaces III
O 43.1: Talk
Wednesday, March 28, 2012, 10:30–10:45, MA 043
STM and STS study of SrRuO3(001) thin films on SrTiO3(001) — •Martin Trautmann1, Dietrich Hesse2, Ionela Vrejoiu2, and Wolf Widdra1,2 — 1Institut für Physik, Martin-Luther-Universität Halle-Wittenberg — 2MPI für Mikrostrukturphysik, Halle/S.
For applications in oxide-based electronic devices such as ferroelectric heterostructures and non-volatile ferroelectric random access memories the electrode material plays an important role. In this context SrRuO3 has drawn significant attention due to its high conductivity and low lattice misfit with many functional perovskites. In this study a 40 nm thick PLD grown film of orthorhombic SrRuO3 on SrTiO3(001) has been characterized by LEED, AFM, STM and STS. Upon heating to 400∘C in 10−5 mbar of oxygen the film exhibits a well-ordered pseudocubic SrRuO3(001)-(1x1) LEED pattern. The observed surface morphology as determined by STM is characterized by small vacancy islands as has been reported also earlier [1]. Annealing to higher temperatures in an increased O2 atmosphere leads to a rearrangement of the vacancy islands in the high symmetry directions. STS on this SrRuO3(001) surface is dominated by a well-resolved unoccupied density-of-states feature at 2.5 eV above EF which is assigned to an unoccupied Ru 4d state on the basis of DFT calculations [2].
[1] H. N. Lee, H. M. Christen, M. F. Chisholm, C. M. Rouleau, and D. H. Lowndes, Appl. Phys. Lett. 84, 4107 (2004)
[2] J. M. Rondinelli, N. M. Caffrey, S. Sanvito, and N. A. Spaldin, Phys. Rev. B 78, 155107 (2008)