visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-10-18 13:30 
연사  
장소 1st fl. #1323(E6-2) 

"Visualization of oxygen vacancy in motion and the interplay with electronic conduction"

 

Dr. Chan-Ho Yang, Department of Physics, KAIST
Oct. 18 (Tue.), 1:30 PM, 1st fl. #1323(E6-2)


Abstract:

The multiferroic BiFeO3 (BFO) is an interesting playground to explore correlated electronic conduction. Here, we substitute divalent Ca ions into the parent BFO and apply an external electric field at elevated temperatures to spatially redistribute spontaneously created oxygen vacancies, thereby generating hole carriers in regions of less dense oxygen vacancy concentrations. X-ray diffraction and photoemission spectroscopic measurement are employed to quantify a large variation of local oxygen vacancy concentration as much as ~1021 cm-3 and explore the consequent evolution of electronic band structure. We find that a non-rigid polaronic band is created by hole doping as a result of a strong electron-lattice coupling. We also show strong evidence for the disorder-driven formation of a Coulomb glass state through electronic transport measurement on a quantitative level. These spectroscopic and transport results can be combined and understood in the framework of intrinsic spatial inhomogeneity of polaronic charge density. Dynamical properties of oxygen vacancy in motion will be also discussed in a spatial-resolved way. The finding offers a promising platform and methodology for examining the interplay of functional defects and correlated electronic behaviors.

 

Contact: SunYoung Choi, (sunyoungchoi@kaist.ac.kr)
Center for Quantum Coherence in Condensed Matter, KAIST

번호 날짜 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
614 2009-02-23 16:00    Physics Colloquium : 2009 Spring file
613 2009-09-07 16:00    Physics Colloquium : 2009 Fall file
612 2009-10-21 16:00    Interdimensional Universality of Dynamic Interfaces
611 2010-02-08 16:00    Physics Ciolloquium : 2010 Spring file
610 2010-02-14 16:00    Physics Colloquium - 2011 Spring file
609 2010-09-06 16:00    Physics Colloquium : 2010 Fall file
608 2011-05-16 16:00    Photonics with surface plasmon polaritons
607 2011-09-03 16:00    Physics Colloquium : 2011 Fall file
606 2012-02-13 16:00    Physics Colloquium : 2012 Spring
605 2012-04-02 16:00    A new route to ferroelectricity in magnetic spinels: a case of Co2MnO4
604 2013-03-11 16:00    Physics Colloquium : 2013 Spring
603 2013-09-09 16:00    Physics Colloquium : 2013 Fall
602 2014-03-10 16:00    Physics Colloquium : 2014 Spring file
601 2014-05-28 17:00    부품소재산업이 미래다
600 2014-12-22 14:00    Dynamics of molecular motors: Power stroke vs Brownian ratchet file
599 2015-03-04 12:00    Bioimaging and Biosensing Using Near-Infrared Fluorescence file
598 2015-03-09 16:00    Physics Colloquium : 2015 Spring file
597 2015-03-13 14:00    The 15th Innovative Workshop on Soft/Bio Materials file
596 2015-06-03 12:00    The First Wednesday Multidisciplinary Forum file
595 2015-07-15 14:00    Electronic and optical properties of titanate-based oxide superlattices