Hideaki Kasai Department of Precision Science and Technology & Applied Physics
Osaka University, Japan
「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-
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
AB INITIOCALCULATIONS
PHYSICAL MECHANISM
VIRTUAL TEST MATERIAL
Experiment
QUANTIZATION ofMECHANISM
FUNCTIONALVERIFICATION
ANALYSIS ofRESULTS
VERIFICATION
触媒デザイン 反応プロセスデザイン
Computational Materials Design® (CMD®)
Magnetic atoms on metal surface
Dr.Emi Minamitani 南谷英美
Real space observation of Kondo effect and RKKY interaction
Numerical Renormalization Group
Kondo effect & local spin interaction
Results, the separation dependence of the RKKY interaction
Spin-spin correlation function shows the oscillatory behavior due to the RKKY interaction in 2D. )( 12
221 RkJSS F
DRKKY
The strongest FM interaction at kFR12=0.9
The strongest AF interaction at kFR12=2.5
)(041.0),(3.0 eVeVU Parameters are set as
FM
AF
Nghiem Thi Minh Hoa
Magnetic adatoms on a metal surface:
- Kondo effect at a single adatom
+- RKKY, and direct interaction between
adatoms- Dimer-
Magnetic order?Frustration?
–Trimer-D3
The trimer problem
N. T. M. Hoa, W. A. Diño, and H. Kasai: J. Phys. Soc. Jpn. 81 (2012) 023706
t13
t12
R12
R13
Yosida-Kondo dominant regime
Magnetic frustration regime
Transition in the trimer system
N. T. M. Hoa, W. A. Diño, and H. Kasai: J. Phys. Soc. Jpn. 81 (2012) 023706.
Critical crossover
Dr. Tomoya Kishi (KOBELCO, Kobe Steel Co.)
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
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.1 0.2 0.3 0.4 0.5
Spin polarized GGA
Fe Thin Film on Cu(111) Fe Thin Film on Cu(111)
EF
Majority spin
Minority spin
Surface state
Surface state
Surface Spintronics Device (PCT2004)
Surface Spintronics Device (PCT2004)
Spin Switch DeviceSpin Memory Device
Spin Switch DeviceSpin Memory Device
Ballistic Spin Circuit (BSC)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、④ スピン伝導ドレイン端子、⑤ スピン伝導ソース端子、
Spin Flip
特願2003-179726号 ,
SURFACE-SPINTRONICS DEVICE
Patent No.: US 7,432,573 B2Date 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
Mary Clare Escaño D3
O2
anions/noble metals
bimetallic surfaces
Nanostructures/CNT
“I am working on gas-metal surface interaction and
diffusion in nanostructures/CNT
composites.”
O2 trajectories
O2 dissociative adsorption favors bridge-
hollow-bridge (b-h-b) configuration on both
systems (Pt and PtFe) – direct dissociation
mechanism in agreement with experiment.
MC Escano, H. Nakanishi, H. Kasai JPC 113 52 (2009)
0.80 1.30 1.80 2.30 2.80 3.30 -2.80
-2.40
-2.00
-1.60
-1.20
-0.80
-0.40
0.00
0.40
Pt(001)
Pt/Fe
Reaction coordinate (Å)
PE (e
V) on Pt/Fe: No barrier!
Potential energy curves for O2 dissociative adsorption on Pt/Fe(001) and Pt(001)
Low Oad binding
Pt/Fe
Pt
O2 dissociative adsorption
b-h-b
Potential energies are relative to gas phase O2 and isolated slab.
Adsorbed:O-O distance 2.80ÅO-Pt distance 1.30 Å
TSO-O distance 1.30ÅO-Pt distance 2.80 Å
Eac on Pt = 0.16eV
Bradley, J. M.; Guo, X. C.; Hopkinson, A.; King, D. A. J. Chem. Phys. 1996, 104, 11. (exp)
Hirofumi Kishi D3
Resistance Random Access Memory : RRAM
RRAM の抵抗変化の解明
①
②
A
• Design of non-precious metal fuel cell electrode materials
Mohammad Kemal Agusta D3