Domain wall current, ferroelectric, and piezoelectric properties of flexible SrBi₂Ta₂O₉ thin films affected by the distribution of a-oriented domains and c-oriented domains

We investigated the ferroelectric, piezoelectric, and domain wall current properties affected by the distribution of a-oriented domains and c-oriented domains in flexible SrBi₂Ta₂O₉ (SBT) thin films on flexible Pt/mica substrates. On the flexible Pt/mica substrates, the SBT thin films with a mixed crystallinity of a-oriented and c-oriented crystallinities exhibited the domain structures mixed with a-oriented domains and c-oriented domains. The SBT thin films with excellent a-oriented crystallinity showed improved ferroelectric and piezoelectric properties due to the polar axis perpendicular to the c-axis. In particular, 90^o domain walls composed of a-domain and c-domain have larger domain wall currents than 180^o domain walls composed of c-domains, which increases the leakage current of the SBT thin films.