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South China University of Technology PowerPoint Presentation
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South China University of Technology

South China University of Technology

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South China University of Technology

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  1. South China University of Technology Structural Relaxation Xiaobao Yang Department of Physics http://www.compphys.cn/~xbyang/lectures.html www.compphys.cn

  2. Schrödinger Equation

  3. Structural relaxation To obtain the ground state relaxed geometry of the system. the equilibrium lattice constants a given ionic configuration the forces obtained these forces are greater than some minimum tolerance the ions are moved in the direction of the forces

  4. Review of QN,SD and CG Conjugate Gradient Steepest descent method

  5. Strain stabilized nanostructures PRL 100, 175503 (2008) ; 107, 236101 (2011)

  6. Stabilities for various coverage

  7. Defect formation energies NELECT @ INCAR Default (number of valence electrons) NELECT = number of electrons

  8. Low dimensional structures • Clusters • Surface • Sheet • Nanotubes and nanowires Nature 318,162(1985); 407,60(2000) PRL 66,2762(1991);Nat. Mater. 6, 183(2007) Science 289,606(2000);299,1874(2003) Nat. Nanotec. 1,103(2006)

  9. Carbon nanotubes Nature 388,756(1997); Science 306,1362(2003) PRL 68,1579(1992); Nature 391,62(1998)

  10. Zone folding

  11. Possible Adsorption Rev. Mod. Phys. 73, 857(2001) Science 289,1324(2000); PRL 84,4621(2000); Nature 412,802(2001); PRL 92,245507(2004); PRL 85,5384(2000)

  12. Applications • Lithium battery • Work function • Hydrogen storage • Spin polarization PRL 85,1706(2000); 88,075506(2002) Science 290, 1552(2000); Nature 388,255(1997) APL 76, 4007(2000); 89, 263113(2006) APL 77, 3015 (2000); Nano. Lett. 4, 561(2004); PRL 94, 175501 (2005) <<

  13. Alkali-metal atoms adsorption

  14. Modulation of electronic properties

  15. Quantum Confinement

  16. Nanotubes from CNT JACS 124,14464(2002); PRL 81, 2332(1998) PRL 95, 116102(2005);APL 86, 231901(2005).

  17. Silicon nanotubes

  18. Why semiconducting? PRB 72,195426(2005)

  19. Boron nanostructures Nat. Mater. 2, 827(2003); PNAS 102,961(2005); PRL 98,166804(2007);JPCB 108,3967(2004); PRB 74,035413(2006)

  20. Stable sheet and nanotubes PRL 99,115501(2007)

  21. Rolling metal into semiconductor PRB 77,R041402(2008)

  22. <112> Si NWs (110) (110) (111) (111) LDOS distribution determines the band gap characteristic. APPLIED PHYSICS LETTERS 93, 173108(2008)

  23. Homework How to obtain carbon nanotubes? Sending to 17273799@qq.com when ready For lecture notes, refer to http://www.compphys.cn/~xbyang/