Domain walls as mobile functional interfaces

Ferroelectric domain-walls are interfaces that separate between regions, domains, inside the ferroelectric in which the spontaneous polarization is differently oriented. The thickness of domain-walls is typically 1-3 nm. Following recent advances in force and electron microscopy, we are investigating internal structure and properties of domain walls and their control. We identified several types of domain walls that are metallic conductors 1,2,3,4 (inside the insulating material) and learnt how to create, eliminate and recreate them 5 and control their density 6. Ferroelectric boundaries were evidenced in non-ferroelectric materials, whose displacement can be controlled by electric field gradient. In another direction, we elaborated ways to create patterns of ultra-high-density domain arrays with controlled domain-wall periodicity of 6-10 nm and showed their electrical erasure and recreation at room temperature.8Domain wall propagation is directed and controlled9 and elastic interaction between non-ferroelastic domain walls is possible,10 thus adding ‘building blocks’ for theemerging field of domain-wall reconfigurable nanoelectronics.

1. T. Sluka et al., Nat. Comm. 3, (2012). 2. T. Sluka et al., Nat. Comm. 4, 2389 (2013). 3. I. Stolichnov et al. Nano Letters (2015). 4. P. Bednyakov et al. Sci. Report s 5, 15819 (2015). 5. A. Crassous et al. Nat. Nanotech. 10, 614 (2015). 6. L. Feigl et al., Nat. Comm. 5, 4677 (2014). 7. X.-K. Wei et al., Nat. Comm. 5, 3031 (2014).