Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 81: Oxide and Insulator Surfaces III
O 81.11: Talk
Thursday, April 3, 2014, 18:30–18:45, PHY C 213
Stress measurements during PLD growth of BaTiO3 and SrTiO3 films on single crystal metal substrates — •Jörg Premper1, Dirk Sander1, and Jürgen Kirschner1,2 — 1Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle — 2Institut für Physik, Martin-Luther-Universität, Halle, Germany
The in situ measurement of film stress by the optical 2-beam cantilever deflection technique [1] is used to study the correlation between stress and strain in BaTiO3 and SrTiO3 monolayers on Fe, Pd and Pt single crystal surfaces of different orientations. These films are grown by pulsed laser deposition (PLD). We find that the deposition of 18 uc (unit cells) BaTiO3 on Pt(001) (misfit = −2.3%) leads to a compressive film stress of −4.2 GPa, whereas the deposition of SrTiO3 (misfit = +0.4%) induces a tensile stress of +1.5 GPa. On Pd(001) the measured film stress for BaTiO3/Pd(001) is −2.6 GPa (misfit = −3.0%) and for SrTiO3/Pd(001) −2.0 GPa (misfit = −0.4%). The comparison between measured stress and calculated misfit-induced stress in the framework of continuum elasticity, considering elastic anisotropy, reveals a qualitative agreement between experiment and stress calculations. This identifies epitaxial misfit as one decisive contribution to film stress in BaTiO3 and SrTiO3 atomic layers. In contrast, no epitaxial order of BaTiO3 and SrTiO3 films on Fe(001) was observed for PLD at 420∘C by LEED. Still film stress of +2.1 GPa and +3.8 GPa is measured. The results are discussed in view of substrate-mediated strain and the influence of growth conditions.
[1] J. Premper, D. Sander, and J. Kirschner, RSI 83, (2012), 073904