Structural Dynamics and Electrical Conduction of Ferroelectric Domain Walls in Hexagonal (Sc,Lu)FeO<sub>3</sub>
ORAL
Abstract
Electrical conduction due to mobile carriers in ferroelectric domains and domain walls has been extensively studied in recent years for their potential applications in nano-electronics. On the other hand, the dielectric loss due to dipolar relaxation and domain wall oscillations is of paramount important for ferroelectric devices working at radio and microwave frequencies. Using a combination of conductive atomic force microscopy (C-AFM) and scanning microwave impedance microscopy (MIM), we demonstrate the local conductivity mapping at both dc and GHz frequencies in hexagonal (Sc,Lu)FeO3 single crystals. Interestingly, while free carriers are responsible for the contrast observed at oppositely polarized domains, the MIM signals at the DWs are clearly dominated by a localized vibrational mode. In particular, the effective GHz conductivity of the DWs, which shows little dependence on the tip bias, is 2 ~ 3 orders of magnitude higher than that at zero-frequency. Our results provide new impetus to incorporate the nanometer-sized ferroelectric DWs into novel high-frequency devices.
–
Presenters
-
Xiaoyu Wu
- Univ of Texas, Austin
- Department of Physics, University of Texas at Austin