Berlin 2012 – wissenschaftliches Programm

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MI: Fachverband Mikrosonden

MI 4: 100 years since the Laue experiment: Topical aspects of diffraction and scattering (Joint Session KR, BP, DF, GP, MA, MI, MM; related to SYXD)

MI 4.11: Vortrag

Dienstag, 27. März 2012, 12:30–12:45, EMH 225

Reconstruction phenomena at the interfaces of LaCoO₃ single films: A resonant x-ray reflectivity study — •Jorge E. Hamann-Borrero^1,2, Abdullah Radi², Woo Seok Choi³, Sebastian Macke⁴, Ronny Sutarto⁵, Feizhou He⁵, George A. Sawatzky², Ho Nyung Lee³, and Vladimir Hinkov⁴ — ¹IFW-Dresden — ²University of British Columbia, Vancouver, Canada — ³Oak Ridge National Laboratory, Materials Science and Technology Division, USA. — ⁴Max Planck-UBC Centre for Quantum Materials, Vancouver, Canada — ⁵Canadian Light Source, Saskatoon, Canada

A series of LaCoO₃ (LCO) single films grown on polar NdGaO₃ (NGO) and non polar SrTiO₃ (STO) substrates were studied by means of Resonant Soft X-ray Reflectivity (RXRR) and X-ray Absorption Spectroscopy (XAS). The RXRR measurements were performed at photon energies close to the Co L_2,3 edges. The detailed analysis of the energy dependent measurements at fixed Q values corresponding to maxima and minima of the RXRR Kiessig fringes reveals a strong signal contribution to the line-shapes which can not be attributed to pure Co³⁺. By considering the polar nature of the LCO structure we find that, at interfaces with polar discontinuity, e.g., at LCO/STO and LCO/Vaccum, reconstruction phenomena take place.

The work at Oak Rigde National Laboratory was supported by the U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division.