• Board
  • Research Highlight
Research HighLight
Research HighLight

[professor Lee, Daesu] Colossal flexoresistance in dielectrics

FILES
  • No attach File
Journal Nature Communications 11, 2586 (2020)
Professor in charge이대수 교수
Lookup44
Author최고관리자
Release date2020-05-22

main text

a77cb29c7a3e917ba793c8624b06e38d_1590473354_298.png
Caption: (Left) Generation of flexoelectric polarization in ultrathin SrTiO3. (Right) Colossal flexoresistance effect, realized via flexoelectricity in ultrathin SrTiO3.

 

 

Dielectrics have long been considered as unsuitable for pure electrical switches; under weak electric fields, they show extremely low conductivity, whereas under strong fields, they suffer from irreversible damage. Here, we show that flexoelectricity enables damage-free exposure of dielectrics to strong electric fields, leading to reversible switching between electrical states—insulating and conducting. Applying strain gradients with an atomic force microscope tip polarizes an ultrathin film of an archetypal dielectric SrTiO3 via flexoelectricity, which in turn generates non-destructive, strong electrostatic fields. When the applied strain gradient exceeds a certain value, SrTiO3 suddenly becomes highly conductive, yielding at least around 108-fold decrease in room-temperature resistivity. We explain this phenomenon, which we call the colossal flexoresistance, based on the abrupt increase in the tunneling conductance of ultrathin SrTiO3 under strain gradients. Our work extends the scope of electrical control in solids and inspires further exploration of dielectric responses to strong electromechanical fields. 

 

top_btn
logo_mobile close_mobile