Conducting Domain Walls in Lithium Niobate Single Crystals

Ferroic materials play an increasingly important role in novel (nano)electronic devices. Recently, research on domain walls (DWs) receives a big boost by the discovery of DW conductivity (DWC) in BiFeO3 and Pb(ZrxTi1-x)O3 ferroic thin films. Here, it is demonstrated that DWC is not restricted to thin films, but equally applies to millimeter-thick wide-bandgap, ferroic single crystals, such as LiNbO3. In this material transport along DWs can be switched by super-bandgap illumination and tuned by engineering the tilting angle of DWs with respect to the polar axis. The results are consistently obtained using conductive atomic force microscopy to locally map the DWC and macroscopic contacts, thereby in addition investigating the temperature dependence, DW transport activation energies, and relaxation behavior.