Regensburg 2019 – wissenschaftliches Programm
CPP 15: Symposium SYCO of the divisions MM (leading), O, CPP, KFM and DS continued as topical session: Mechanically controlled electrical conductivity of oxides (joint session MM/CPP/O)
CPP 15.2: Vortrag
Montag, 1. April 2019, 16:15–16:30, H46
Characterization of Fe:STO thin films prepared by pulsed laser deposition — •Maximilian Morgenbesser, Stefanie Taibl, Markus Kubicek, Alexander Viernstein, Christopher Herzig, Andreas Limbeck, and Jürgen Fleig — TU Wien, Wien, Österreich
The perovskite-type oxide SrTiO3 (STO) is one of the best investigated materials in solid state ionics and commonly used as a model material in solid state ionics. The defect model of bulk SrTiO3 is well understood and the conductivity of bulk samples can be tailored by acceptor or donor doping, e.g. with Fe3+ or Nb5+ on the Ti4+ site. However, other aspects of SrTiO3 have not been understood so far, for example the the influence of factors such as stoichiometry and strain on the conductivity which is investigated in this study.
Two different kinds of 2 % Fe-doped thin films were deposited by pulsed laser deposition (PLD). Thin films deposited from stoichiometric targets exhibit a low, intrinsic conductivity. In addition, targets with Sr overstoichiometry were used and the conductivity could be increased by four orders of magnitude. The thin films are compared to each other in regard to the structure and stoichiometry. Structural differences could be found by x-ray diffraction measures, revealing a difference in lattice parameters. The chemical composition was analyzed by means of inductively coupled plasma optical emission spectroscopy (ICP-OES) and differences in the A/B ratios could be found. A model linking the conductivity to the stoichiometry of the thin films is presented, highlighting the possible impact of cation vacancies and antisite defects on the electrical conductivity of Fe:SrTiO3.