SKM 2021 – scientific programme

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 5: Poster Session KFM

KFM 5.17: Poster

Tuesday, September 28, 2021, 16:00–17:00, P

Tracking ferroelectric domain formation during epitaxial growth of PbTiO3 films — •Martin F. Sarott, Manfred Fiebig, and Morgan Trassin — Department of Materials, ETH Zurich, Switzerland

The pronounced impact of growth conditions on the formation of domains in ferroelectric thin films obstructs the effective design of devices based on ferroelectrics that require controlled polarization states. Here, we overcome this notorious difficulty by tracking in-situ, during growth, the ferroelectric domain formation in ultrathin films of the tetragonal ferroelectric model system PbTiO3. By combining in-situ optical second harmonic generation (ISHG) with post-growth piezoresponse force microscopy and ex-situ SHG imaging, we identify the thickness threshold for the epitaxial strain-driven partial conversion of out-of-plane polarized c-domains into in-plane oriented a-domains during the deposition. Furthermore, we find that in the strongly compressive regime the formation of a-domains is triggered during the early stages of growth, which favors a remarkable randomization in the distribution of a- and c-domains upon further deposition. This extraordinary heterogeneity is reminiscent of the domain distribution at the morphotropic phase boundary in technologically relevant PZT and thus highlights the significance of control over the c-to-a domain interconversion for applications.