Formation of ferroelectric charged domain walls in tetragonal phase

Charged domain walls (CDWs) in proper ferroelectrics are structural interfaces possessing metallic-like conductivity [1,2]. Unlike conventional heterointerfaces, these walls can be displaced inside a dielectric by an electric field, which is of interest for future electronic circuitry.

Here we discuss the formation of CDWs in BaTiO₃ single crystals. Throughout the last decade, various engineering techniques of ferroelectric CDWs were intensively developed, however, the understanding of the process of CDWs’ formation is still very limited.

It was shown that the formation of ferroelectric CDWs in BaTiO₃ single crystals takes place during the phase transition to tetragonal phase either from cubic [3] or from orthorhombic [4] phases. In the present work, we demonstrate that in BaTiO₃ single crystals CDWs can be engineered even in tetragonal phase without inducing the phase transition (fig.1). Formation of CDWs in tetragonal phase is based on free charge carrier generation with ultraviolet light and frustrative poling with DC electric field along direction. The observed evolution of domain pattern with CDWs under mentioned conditions is nontrivial and the system is strongly time dependent.

Fig.1 Process of CDWs growth in tetragonal oriented BaTiO₃ single crystal.

[1] P. Maksymovych, A.N. Morozovska, P. Yu, E.A. Eliseev, Y-H. Chu, R. Ramesh, A.P. Baddorf, and S.V. Kalinin. Nano Lett. 12, 209–213 (2012).

[2] T. Sluka, A. Tagantsev, P. Bednyakov, N. Setter. Nat. Commun, 4, 1808 (2013).

[3] P. Bednyakov, T. Sluka, A.K. Tagantsev, D. Damjanovic & N. Setter. Scientific Rep. 5, 15819 (2015).

[4] P. Bednyakov, T. Sluka, A. Tagantsev, D. Damjanovic, N. Setter. Advanced Materials 28, 9498–9503 (2016).

This work was supported by the Czech Science Foundation (Project No. 20-05167Y).