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MA: Fachverband Magnetismus
MA 3: Magnetic Materials I
MA 3.5: Talk
Monday, March 26, 2007, 11:15–11:30, H22
Interfacial features of La0.7Sr0.3MnO3 probed by scanning tunneling microscopy — •Lakshamana Sudheendra, Markus Esseling, Vasily Moshnyaga, Bernd Damaschke, and Konrad Samwer — I. Physikalisches Insitut, Friedrich-Hund-Platz-1, 37077, Göttingen, Germany
We present scanning tunneling microscopy (STM) and spectroscopy (STS) studies on artificial grain boundary (GB) resulting from the growth of Sr-substituted manganite on MgO bicrystal substrate. The width of the GB-the region between the two crystals- was found to be around 20-30 nm, wherein unusual structural and electronic features were observed in the topography and spectroscopy. Within the GB, structural features running parallel to the grain boundary were detected, which originate probably due to relaxation of stress. Tunneling conductivity within the GB at room temperature was found to be insulating-like, and could be strongly increased through the interaction between the tip and film. The puzzle of sharp [1] versus diffused [2] electronic phase separation between two different electronic phases appears to be linked to domains/antiphase boundaries versus disorder/strain.
[1]. Ch. Renner et al., Nature, 416, 518 (2002).
[2]. T. Becker et al., Phys. Rev. Lett. 89, 237203 (2002).
Acknowledgement: We acknowledge the support of DFG-SFB 602 TP A2 and the Leibniz program.