Berlin 2012 – scientific programme

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SYRS: Symposium Resistive Switching

SYRS 2: Poster: Resistive switching (jointly organized by DS, DF, KR, HL)

SYRS 2.5: Poster

Thursday, March 29, 2012, 17:30–19:00, Poster E

Thermal Conductivity as sensor for defects in homoepitaxial SrTiO3 — •Thilo Kramer¹, Jonas Lindner¹, Stefanie Wiedigen¹, Manuel Feuchter², Marc Kamlah², Inga Knorr¹, Cynthia Volkert¹, and Christian Jooß¹ — ¹University of Göttingen, Institute for Materials Physics — ²Forschungszentrum Karlsruhe, Instiute for Materials Research II

SrTiO3 is a promising material for various future applications in the fields of thermoelectric, oxide electronics or resistive switching, where the control of point defect structure is of high importance. Such defects control the strain and doping level, and, may be involved in resistive switching. Because a direct measurement of defect type and concentrations is difficult, we evaluate whether thermal conductivity can indirectly give access to the desired information via point defect induced phonon scattering. Thin homoepitaxial SrTiO3 films are fabricated with Ion Beam Sputtering. The balance between ion beam induced defect generation and dynamic healing and thus the resulting net defect concentration can be influenced by varying the deposition temperature. The temperature dependence of the thermal conductivity of the thin films is reliably measured by the 3w method in combination with finite element simulations of the thermal conditions. We present systematic study of thermal conductivity as a function of varying preparation conditions. X-ray diffraction, TEM and mechanical measurements allow for detailed insights into the degree of epitaxy and the stress strain state of the films. The combination of all used methods gives evidence that charge neutral Schottky defects are the dominating defect type.