November 2018: Dr Lisha Liu "Frequency-dependent decoupling of domain-wall motion and lattice strain in bismuth ferrite"
"Revealing the mechanisms of decoupled microscopic piezoelectric response in bismuth ferrite using high-energy x-ray diffraction"
Ferroic domain walls are naturally occurring nanoscale interfaces that can possess distinct properties from their parent materials. Due to their length scale, they have generated great interest for applications such as domain wall nanoelectronics. The ferroelectric material BiFeO3 has been shown to possess enhanced electrical conductivity at domain wall regions. This ferroelectric material also displays Maxwell–Wagner-like frequency dispersion in its macroscopic piezoelectric response when in bulk ceramic form. This dispersion, which is different from a prototypical linear frequency-dependent behaviour in classical ferroelectric materials, has been suggested to originate from the conductive domain walls. This study used in situ high-energy x-ray scattering at the European Synchrotron and developed an analytical model to reveal the underlying microstructural inhomogeneity that leads to this type of frequency dispersion.
Read the full paper, as published in Nature Communications 9, Article number: 4928 (2018).