「コンピューティックスによる物質デザイン:複合相関と非平衡ダイナミクス」研究会 2012年3月16日(金)-3月17日(土) 東京大学本郷キャンパス Computational Materials Design –from basics to applications- Hideaki Kasai Department of Precision Science and Technology & Applied Physics Osaka University, Japan Spin Manipulation at Surfaces 1. Kondo Effect and Influence of the RKKY Interaction (Magnetic Dimer, Trimer) 2. Surface-Spintronics Device Magnetic Layer (Fe) on Non-Magnetic Substrate (Cu) 3. Catalyst for Oxygen Reduction Reaction Non-Magnetic Layer (Pt) on Magnetic Substrate (Fe) Effect of Oxygen Vacancy 4. Resistance Random Access Memory FAX:06-6879-7859 Computational Materials Design® (CMD®) FUNCTIONAL VERIFICATION VIRTUAL TEST MATERIAL AB INITIO CALCULATIONS 触媒デザイン 反応プロセスデザイン ANALYSIS of RESULTS PHYSICAL MECHANISM QUANTIZATION of MECHANISM Experiment VERIFICATION Dr.Emi Minamitani南谷英美 Real space observation of Kondo Numerical effect and RKKY interaction Renormalization Group Results, the separation dependence of the RKKY interaction Spin-spin correlation function shows the oscillatory behavior due to the RKKY interaction in 2D. S S J 2 D (k R 1 2 RKKY F 12 ) The strongest FM interaction at kFR12=0.9 FM AF The strongest AF interaction at kFR12=2.5 Parameters are set as U 0.3(eV ), 0.041(eV ) Magnetic adatoms on a metal surface: - Kondo effect at a single adatom + - RKKY, and direct interaction between adatoms -DimerMagnetic order? Frustration? –TrimerD3 Nghiem Thi Minh Hoa The trimer problem Yosida-Kondo dominant regime t13 R12 t12 R13 N. T. M. Hoa, W. A. Diño, and H. Kasai: J. Phys. Soc. Jpn. 81 (2012) 023706 Magnetic frustration regime Transition in the trimer system Critical crossover N. T. M. Hoa, W. A. Diño, and H. Kasai: J. Phys. Soc. Jpn. 81 (2012) 023706. 博士論文 表面ナノ構造の磁性と伝導性に 関する理論的研究(2005) Magnetic and Transport Properties of Surface Nano-Structures Dr. Tomoya Kishi (KOBELCO, Kobe Steel Co.) Fe Thin Film on Cu(111) 2 1.5 1 0.5 EF Spin polarized GGA 0 0 0.1 0.2 0.3 0.4 0.5 -0.5 Majority spin Surface state -1 Minority spin -1.5 Surface state -2 Surface Spintronics Device (PCT2004) Ballistic Spin Circuit (BSC) ①膜厚が数原子層分の鉄原子薄膜、 ②鉄原子薄膜を支える(111)面を上面にした銅 薄膜 ③銅薄膜支持バッファー層基板、 Spin Flip ④スピン伝導ドレイン端子、 ⑤スピン伝導ソース端子、 特願2003-179726号, Spin Switch Device Spin Memory Device SURFACE-SPINTRONICS DEVICE Patent No.: US 7,432,573 B2 Date of Patent: Oct. 7, 2008 Inventors: Hideaki Kasai, Osaka (JP); Hiroshi Nakanishi, Osaka (JP); Tomoya Kishi, Hyogo (JP) PCT No.: PCT/JP2004/009226 CMD: Case Study Quantum Simulation and Design of Novel Catalytic Materials for Energy Applications 新規高効率エネルギー技術開発のための量子シミューレション・マテリアル・デザイン anions/noble metals O2 Nanostructures/CNT bimetallic surfaces “I am working on gas-metal surface interaction and diffusion in nanostructures/CNT composites.” Mary Clare Escaño D3 O2 dissociative adsorption Potential energy curves for O2 dissociative adsorption on Pt/Fe(001) and Pt(001) O2 trajectories 0.40 Eac on Pt = 0.16eV 0.00 PE (eV) -0.40 Pt/Fe -0.80 on Pt/Fe: No barrier! -1.20 -1.60 Pt -2.00 b-h-b Pt(001) Low Oad binding -2.40 -2.80 Pt/Fe Potential energies are relative to gas phase O2 and isolated slab. 0.80 O2 dissociative adsorption favors bridgehollow-bridge (b-h-b) configuration on both systems (Pt and PtFe) – direct dissociation mechanism in agreement with experiment. 1.30 1.80 2.30 Reaction coordinate (Å) 2.80 Adsorbed: O-O distance 2.80Å O-Pt distance 1.30 Å TS O-O distance 1.30Å O-Pt distance 2.80 Å Bradley, J. M.; Guo, X. C.; Hopkinson, A.; King, D. A. J. Chem. Phys. 1996, 104, 11. (exp) MC Escano, H. Nakanishi, H. Kasai JPC 113 52 (2009) 3.30 Resistance Random Access Memory:RRAM ② ① A RRAMの抵抗変化の解明 Hirofumi Kishi D3 • Design of nonprecious metal fuel cell electrode materials Mohammad Kemal Agusta D3
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