Conduction at Domain Walls in Insulating Pb(Zr_0.2Ti_0.8)O₃ Thin Films

Abstract

Domain wall conduction in insulating Pb(Zr(0.2) Ti(0.8))O(3) thin films is demonstrated. The observed electrical conduction currents can be clearly differentiated from displacement currents associated with ferroelectric polarization switching. The domain wall conduction, nonlinear and highly asymmetric due to the specific local probe measurement geometry, shows thermal activation at high temperatures, and high stability over time.

Towards reversible control of domain wall conduction in Pb(Zr0.2Ti0.8)O3 thin films

“…In contrast to PZT STO , where domain wall conduction is observed at low voltages, followed by displacement currents at higher voltages, 3 we detected no domain-wall-specific currents in as-grown PZT DSO . Rather, both at domain walls and within the domain regions, we observe only insulating behavior at low voltages as shown by CAFM measurements with the tip bias incremented by À0.5 V every 10 lines in Fig.…”

“…Combining dual frequency resonance tracking (DFRT) piezoresponse force microscopy 16 (PFM) and conductive-tip atomic force microscopy (CAFM) measurements 17 3 substrates by off-axis radiofrequency magnetron sputtering, and showed similarly smooth surfaces without detectable presence of a domains. All samples are monodomain up-polarized (bright contrast in Figs.…”

“…In particular, electrical conductance at ferroelectric domain walls in otherwise insulating wide-bandgap (multi)ferroics such as BiFeO 3 3 has attracted much interest as a pathway towards domain-wall-based nanoelectronics. [4][5][6] The intrinsic conductance of charged domain walls 7,8 is related to the head-to-head or tail-to-tail orientation of the polarization vector, and therefore modifiable only by changes to the domain geometry itself, 9 limiting its applicability in device design.…”

Localized states in advanced dielectrics from the vantage of spin- and symmetry-polarized tunnelling across MgO

“…In conclusion, we have taken spin-and symmetry-polarized tunnelling across MgO as a canonical example of the need to take into account the electronic structure of defect sites in oxide semiconductors for advanced applications [62][63][64] . We have provided and highlighted an explicit description of thermally activated defect-assisted magnetotransport by utilizing solid-state tunnelling spectroscopy 55 to probe the ground and excited states of oxygen vacancies 49,52 .…”

Local conductivity and the role of vacancies around twin walls of (001)−BiFeO3 thin films

“…This becomes now essential because, according to recent reports, conduction at domain walls is a rather general phenomenon [19], only the most relevant mechanisms seem to vary. As one can expect, different conduction mechanisms are likely to have different relevance in different types of walls.…”