Dynamic ferroelectric hysteresis scaling of four-layered Aurivillius phase CaBi4Ti4O15 thin films

The hysteresis loop area represents the energy dissipation within one complete period of domain reversal, and it has been demonstrated that the scaling relation between ⟨A⟩ with electric field E and frequency f follows the power law in most systems as ⟨A⟩∝faEb. The evolution of dynamic hysteresis loops with electric field and frequency in ferroelectric CaBi4Ti4O15 thin films has been systematically investigated. At low electric fields, the scaling relation for the hysteresis loops of the thin films is ⟨A⟩∝f−0.0985E2.6939, while at high electric fields, the scaling relation is ⟨A⟩∝f−0.0985E2.0061. Both cases differ significantly from that of the theoretical prediction and also of the other lower l Aurivillius phase thin films. This indicates that the scaling relation is layer-structure and composition dependent. A relatively small value of index a is obtained in comparison with other ferroelectric materials, which imply that the thin films are less frequency-dependent and show more stable ferroelectric domain inversion than the others. All results demonstrate that the thin films possess excellent frequency stability and hysteresis is more dependent on the electric field rather than the frequency.