2006 Fiscal Year Final Research Report Summary
Electronic Structure of Correlated Transition-Metal Oxides under Epitaxial Strain Control of Single Crystal Thin Films
| Project/Area Number |
16204024
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | The University of Tokyo |
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Principal Investigator |
FUJUMORI Atsushi The University of Tokyo, Graduate School of Science, Professor, 大学院理学系研究科, 教授 (10209108)
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| Co-Investigator(Kenkyū-buntansha) |
OSHIMA Masaharu The University of Tokyo, Graduate School of Engineering, Professor, 大学院工学系研究科, 教授 (30280928)
MIZOKAWA Takashi The University of Tokyo, Graduate School of Frontier Sciences, Associate Professor, 大学院新領域創成科学研究科, 助教授 (90251397)
OKANE Tetsuo Japan Atomic Energy Association, Synchrotron Radiation Research Center, Associate Scientist Chief, 放射光科学研究センター, 副主任研究員 (10391278)
TERAI Kouta Japan Atomic Energy Association, Synchrotron Radiation Research Center, Postdoctoral Fellow, 放射光科学研究センター, 博士研究員 (00373241)
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| Project Period (FY) |
2004 – 2006
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| Keywords | Transition-Metal Oxide / Ultra-thin Film / Pulsed Laser Deposition / Photoemission Spectroscopy / Ferromagnetism / Strong Correlation / Nano Structures |
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| Research Abstract |
*We determined the band structures and the Fermi surfaces of three-dimensional perovskite-type oxides such as La_<1-x>Sr_xFeO_3 and La_<1-x>Sr_xMnO_3 by in-situ photoemission spectroscopy of single-crystalline thin films grown using laser molecular-beam epitaxy.
*In order to understand the mechanism how ferromagnetism appears in the pseudo-binary alloy CaMn_<1-x>RuxO_3 (CMRO) formed between the paramagnetic metal CaRuO_3 and the antiferromagnetic semiconductor CaMnO_3, soft x-ray circular dichroism measurements were performed and the antiparallel alignment of the Mn and Ru spins were found.
*Charge transfer at various hetero-interfaces has been studied by utilizing resonant photoemission techniques. We found thatwhile there is Fe-to-Mn charge transfer at the La_<0.6>Sr_<0.4>FeO_3/La_<0.6>Sr_<0.4>MnO interface, no Mn-to-Ti charge transfer was detected for SrTiO_3/La_<0.6>Sr_<0.4>MnO_3.
*Core levels at the SrTiO_3/YBa_2Cu_3O_<7-d> interfaces were found to be shifted after UV-light irradiation and resultingphoto-carrier injection. From the excitation frequency dependence of the shifts, the lifetime of the injected carriers was estimated.
*Metallic states were observed at the interfaces between the Mott insulator LaTiO_3 and the band insulator SrTiO_3 using photoemission spectroscopy, whereas no metallic states were observed between another Mott insulator VO_2 (in the low temperature phase) and the band insulator TiO_2. The results imply the importance of polarity discontinuity at the interface to induce metallic states out of insulating materials.
*The built-in potential at the all oxide p-n junction ZnO/NiO interface were determined using a new method combining core-level photoemission spectroscopy and Ar-ion sputtering.
*180-degree magnetic domains in La_<0.6>Sr_<0.4>MnO_3 thin films were found to be induced by the steps of the substrate using photoemission electron microscopy.
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Research Products
(97 results)
