Dresden 2017 – scientific programme

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DS: Fachverband Dünne Schichten

DS 44: Postersession II

DS 44.11: Poster

Thursday, March 23, 2017, 17:00–19:00, P1C

Photo-induced effects in hole-doped La_1−xSr_xMnO₃ (0<x≤0.1) films probed by Raman spectroscopy — •Christoph Meyer, Sebastian Merten, Bernd Damaschke, and Vasily Moshnyaga — I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen

Perovskite manganite La_1−xSr_xMnO₃ (LSMO) displays a variety of structural, electric and magnetic phases with different types of crystallographic distortions, e.g. the Jahn-Teller effect, manifesting themselves in colossal magnetoresistance effect and insulator-metal transition. To monitor and to disentangle the influence of light, temperature and doping on the structure, we grew series of hole-doped LSMO (0≤x≤0.3) epitaxial thin films on LaAlO₃ (100) and MgO (100) substrates by metalorganic aerosol deposition and probed them by polarization-dependent Raman spectroscopy. The Raman spectra were studied as a function of the Sr content, temperature and laser power to determine a photo-induced effect. The emergence of the metallic phase, marked by the Raman mode at ∼430 cm⁻¹ and a simultaneous suppression of the Jahn-Teller bands at ∼510 cm⁻¹ and ∼630 cm⁻¹ by increasing the laser power for the insulating LSMO films with 0<x≤0.1 was observed. The results are rationalized as a photo-induced shift towards metallic phase, equivalent to the increase of Sr-doping x>0.15 in the LSMO phase diagram. Financial support by the DFG via project SFB 1073/B04 is gratefully acknowledged.