標題: Unexpected Giant Microwave Conductivity in a Nominally Silent BiFeO3 Domain Wall
作者: Huang, Yen-Lin
Zheng, Lu
Chen, Peng
Cheng, Xiaoxing
Hsu, Shang-Lin
Yang, Tiannan
Wu, Xiaoyu
Ponet, Louis
Ramesh, Ramamoorthy
Chen, Long-Qing
Artyukhin, Sergey
Chu, Ying-Hao
Lai, Keji
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: ac conductivity;bismuth ferrite;domain wall nanoelectronics;microwave microscopy
公開日期: 1-Jan-1970
摘要: Nanoelectronic devices based on ferroelectric domain walls (DWs), such as memories, transistors, and rectifiers, have been demonstrated in recent years. Practical high-speed electronics, on the other hand, usually demand operation frequencies in the gigahertz (GHz) regime, where the effect of dipolar oscillation is important. Herein, an unexpected giant GHz conductivity on the order of 10(3) S m(-1) is observed in certain BiFeO3 DWs, which is about 100 000 times greater than the carrier-induced direct current (dc) conductivity of the same walls. Surprisingly, the nominal configuration of the DWs precludes the alternating current (ac) conduction under an excitation electric field perpendicular to the surface. Theoretical analysis shows that the inclined DWs are stressed asymmetrically near the film surface, whereas the vertical walls in a control sample are not. The resultant imbalanced polarization profile can then couple to the out-of-plane microwave fields and induce power dissipation, which is confirmed by the phase-field modeling. Since the contributions from mobile-carrier conduction and bound-charge oscillation to the ac conductivity are equivalent in a microwave circuit, the research on local structural dynamics may open a new avenue to implement DW nano-devices for radio-frequency applications.
URI: http://dx.doi.org/10.1002/adma.201905132
http://hdl.handle.net/11536/153744
ISSN: 0935-9648
DOI: 10.1002/adma.201905132
期刊: ADVANCED MATERIALS
起始頁: 0
結束頁: 0
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