Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 47: Correlated Electrons: Other Materials

TT 47.7: Vortrag

Mittwoch, 9. März 2016, 12:15–12:30, H23

Phase separation in Y_0.63Ca_0.37TiO₃ — •Thomas Koethe¹, Bernhard Zimmer¹, Raphael German¹, Alexei Barinov², Alexander Komarek^1,3, Fulvio Parmigiani², Markus Braden¹, and Paul van Loosdrecht¹ — ¹II. Physikalisches Institut, Universität zu Köln — ²Elettra Sincrotrone, Trieste (Italy) — ³Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden

We have investigated the domain structure and Raman response of Y_0.63Ca_0.37TiO₃ single crystals which show a clear metal-to-insulator transition at ca. 170 K, with a wide hysteresis in the resistivity ranging down to ca. 50 K. We observe by use of a conventional optical microscope the appearance of two distinct regions at temperatures below ca. 200 K, with a characteristic length scale of order of 10 µm. By means of Raman spectroscopy we can identify the regions to correspond to the metallic and insulating domains, and follow the evolution of the domains as function of temperature down to 5 K. Preliminary results of spacially resolved PES confirm the presence of electronically distinct regions on the µm scale at low temperature.