Seminar & Event
2011년도 제 23차 WCU Seminar 공지 - 2011년 11월 25일
Author
관리자
Date
2011-11-23
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985
1.제 목 : Electronic phase transition in low dimensional oxide superlattices
2.연 사 : Jaichan Lee Ph.D. (Professor, School of Advanced Materials Science and Engineering, Sungkyunkwan University)
3.일 시 : 2011년 11월 25일 (금) 16:00-17:00
4.장 소 : 301동 117호
5.내 용 : We report low dimensional oxide structures made by La doping on SrTiO3, represented by SrTiO3/(Sr1-x,Lax)TiO3 superlattices. The low dimensional transition metal oxide structures provide electronic confinement through orbital reconstruction of d orbital of the transition metal ion and correspondingly exhibit metal to insulator transition with the thickness of SrTiO3 layers. This is contrast to the behavior of bulk SrTiO3 doped with La. The carrier density of the low dimensional structures also had a non-linear relationship with the stacking period while the carrier density of bulk SrTiO3 had a linear relation with La doping content. Through the orbital reconstruction, degenerate narrow 3d bands are lifted and dxy band is shifted lower than dxz, dyz bands, making dxz band the first available state upon the La doping. Moreover, doped electrons occupying dxz band are strongly localized next the doped layer. As a result, the low dimensional oxide structure has two types of carriers, one localized at the interface (La doped layer) and the other extended into SrTiO3 layer, which exhibit quite different transport characteristics from bulk doped case. Transport behavior of such a low dimensional structure can be tuned by varying dimensionality and the corresponding metal-insulator transition is induced.
6. 약 력 :
Major Research Interests :
1. Physical properties and mechanisms of multifunctional artificial oxide systems
2. Thin film process and properties of nanolaminate oxide for oxide electronics
3. Materials design by quantum mechanical computer simulation
Education :
Ph. D. (Ceramic Science and Engineering) 1989 - 1993
Rutgers, The State University of New Jersey, USA (1993)
M.S. (Materials Science and Engineering) 1983 - 1985
Korea Advanced Institute of Science and Technology (KAIST)
B.S. (Metallurgical Engineering) 1979 - 1983
Seoul National University
※ 문 의 : 기계항공공학부 조경재 교수 (880-1709)
