1. Hydrogen Absorbing Materials YOSHIDA Lab. M1 Ryusuke Tominaga

2. The purpose of research The purpose of my research is through creating high-quality Hydrogen Absorbing Materials, to encourage the prevalence of fuel-cell electric vehicle, and thereby to contribute to the energy and environment concern.

3. fuel-cell electric vehicle 「ＰＵＹＯ」 出典： http://www.nikkei.co.jp/news/main/im20071009AS1D0904609102007.html （ ->) （ ->) environment concern The efficiency of fuel-cell electric vehicle is 2 times more efficient than that of normal vehicle (->energy concern) No emissions of carbon dioxide

4. The structure of Fuel cell

5. What is the Hydrogen Absorbing Materials ? The Hydrogen Absorbing Materials are the materials that can absorb and emit hydrogen. The discover ： the Philips Eindhoven institution （ Netherlands)

6. The condition that must be satisfied to be a practical Hydrogen Absorbing system Can the system contain enough fuel for about 480km drive ranges at one time refilling ? Can it release hydrogen at rates fast enough to provide the power and acceleration that drier expect on a freeway ? Can it fill the fuel fast enough at reasonable price ?

7. Specific material ZnO Doping H into T0 Formation energy E f =[E(ZnO:H x )-{E(ZnO)+0.5*x*E(H 2 )}]/x (zincblende) BC: Bond-centered AB: Antibonding T: Tetrahedral H: Hexagonal

8. Condition for calculation Machikaneyama2002 http://sham.phys.sci.osaka-u.ac.jp/~kkr/ Korringa-Kohn-Rostoker (KKR) Green ’ s function method Coherent potential approximation (CPA) Local density approximation (LDA) No lattice relaxationedelt=0.001 Ry, ZnO zincblende structure Experimental lattice constants are used.

9. ZnO

10. 同時ドーピング法 ドープするドナーとアクセプター濃度に アンバランつけながら、同時にドープ する方法。 a ）溶解度増大効果 b) キャリア活性率増大効果 c ）易動度増大効果

11. Specific material ZnO Doping trantion metal into Zn-site Doping H into T0 Formation energy E f =[(E((Zn,X)O:H x )-{E((Zn,X)O)+0.5*x*E(H 2 )}]/x (zincblende) BC: Bond-centered AB: Antibonding T: Tetrahedral H: Hexagonal

13. Condition for calculation Machikaneyama2002 http://sham.phys.sci.osaka-u.ac.jp/~kkr/ Korringa-Kohn-Rostoker (KKR) Green ’ s function method Coherent potential approximation (CPA) Local density approximation (LDA) No lattice relaxationedelt=0.001 Ry, ZnO zincblende structure Experimental lattice constants are used.

15. Ｗｈａｔ ｉｓ ｔｈｅ ｃ ａｕｓｅ ？ LDA error ? Can ZnO be Hydrogen Absorbing Materials ?

16. LDA+SIC ‘ Pseudopotential-like self-interaction correction scheme ’ by Filippetti and Spaldin. We implement the scheme with KKR-CPA code (MACHIKANEYAMA2002 ). Filippetti and Spaldin, PRB 67, 125109 (2003). Akai, PRL 81, 3002 (1998). Orbital independent potential

17. ZnVO Ishida et al., Pysica B 351, 204 (2004). LDA SIC Main peak at E B = 1.8 eV

18. Condition for calculation Machikaneyama2002 http://sham.phys.sci.osaka-u.ac.jp/~kkr/ Korringa-Kohn-Rostoker (KKR) Green ’ s function method Coherent potential approximation (CPA) （ Self-interaction corrected LDA (SIC-LDA) ） No lattice relaxationedelt=0.001 Ry, ZnO zincblende structure Experimental lattice constants are used.

20. Other material MgH2

21. Sumarry The co-doping method is efficient to ZnO. But the effect is limited. Using SIC-LDA (Self-interaction corrected LDA) Other material ex) MgH2