Resistance Random Access Memory

Report
「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
FM
AF
The strongest FM interaction
at kFR12=0.9
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
t12

R12
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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