[2015년 1학기 물리학과 콜로퀴엄]
연사: 정창욱 교수 ( 한국외대 전자물리학과 )
제목: The physical properties of SrRuO3 and SrCoOx thin films made by PLD
초록:
Reasonably good conductivity and structural similarity with functional oxide like BaTiO3 and Pb(Zr,Ti)O3 made SrRuO3 useful as an oxide electrode. The control of epitaxial strain with and without growth orientation can modify its magnetic properties dramatically in the thin film of ferromagnetic perovskite oxide. Doping also can change transport properties as well as the magnetic properties of perovskite oxide. In this presentation, I will introduce an overview of our research using thin film of SrRuO3.[1-5] We have used SrTiO3 (001), (110), and (111) substrate to have different film growth orientation. In addition, we have used CaHfO3 and (Ca,Sr)SnO3 to control the amount of epitaxial strain. Doping Fe at Ru site was tried to control the growth mode as well as the magnetic properties. Miscut substrate was used to control the twin problems on the in-plane isotropic substrate. Magnetic anisotropy, ferromagnetic transition temperature, surface morphology, and transport properties changed systematically. These controls should give more freedom on the device design in the oxide thin film. I will end up this talk with our most recent works on the SrCoOx thin films. We discovered the resistance switching phenomena in this compound and proposed a new switching model. [6,7]
References
[1] C. U. Jung, H. Yamada, M. Kawasaki, and Y. Tokura, Appl. Phys. Lett. 84, 2590 (2004).
[2] B. W. Lee, C. U. Jung, M. Kawasaki, and Y. Tokura, J. Appl. Phys. 104, 103909 (2008).
[3] B. W. Lee and C. U. Jung, Appl. Phys. Lett., 96, 102507 (2010).
[4] B. W. Lee and C. U. Jung, J. Kor. Phys. Soc., 59, 322 (2011).
[5] B. W. Lee ,.., and C. U. Jung, Nanoscale Research Letters 2014 9:8. (2014).
[6] H. Jeen, W. S. Choi, J. W. Freeland, H. Ohta, C. U. Jung, and H. N. Lee, Advanced Material, 25, 3651 (2013).
[7] Octolia T. Tambunan,.. C. U. Jung, Appl. Phys. Lett., 105, 063507 (2014).
일시: 5월 21일 목요일 오후 4시 30분
장소: 베어드홀 103호