Strain reduction in supported materials; the formation of cracks and dislocations

Abstract

Supported materials have been constructed by successively depositing ions onto a surface in conjunction with dynamics simulation and energy minimisation. In particular, the growth of SrO/SrO, CaO/SrO (–6.9% misfit) and BaO/SrO (+7.0% misfit) were studied as model systems to examine the influence of the misfit on the structure and stability of epitaxial thin films. At low (theoretical monolayer) coverage, the CaO formed islands on the SrO(001) surface in contrast to the strips formed by BaO. At higher coverages cracks formed within the CaO, while dislocations appeared within the BaO thin film, in both cases to help reduce the strain within the materials. A mechanism for the formation of the dislocation is presented. For one particular CaO/SrO(001) interface, a cubic-hexagonal transformation of the CaO is observed, enabling the misfit to be perfectly accommodated.

References

1. O. Eibl, H. E. Hoenig, J.-M. Triscone, O. Fischer, L. Antognazza and O. Brunner, Physica C, 1990, 172, 365.
2. O. Eibl, H. E. Hoenig, J.-M. Triscone, O. Fischer, L. Antognazza and O. Brunner, Physica C, 1990, 172, 373.
3. R. Ramesh, D. Hwang, T. S. Ravi, A. Inam, J. B. Barner, L. Nazar, S. W. Chan, C. Y. Chen, B. Dutta, T. Venkatesan and X. D. Wu, Appl. Phys. Lett., 1990, 56, 2243.
4. J. Narayan, S. Sharan, R. K. Singh and K. Jagannadham, Mater. Sci. Eng. B, 1989, 333.
5. N. Sridhar, J. M. Rickman and D. J. Srolovitz, Acta. Mater., 1996, 44, 4085.
6. N. Sridhar, J. M. Rickman and D. J. Srolovitz, Acta. Mater., 1996, 44, 4097.
7. D. M. Hwang, T. S. Ravi, R. Ramesh, S. W. Chan, C. Y. Chen and L. Nazar, Appl. Phys. Lett., 1990, 57, 1690.
8. T. S. Ravi, D. M. Hwang, R. Ramesh, S. W. Chan, L. Nazar, C. Y. Chen, A. Inam and T. Venkantesan, Phys. Rev. B, 1990, 42, 10141.
9. D. Dimos, P. Chaudhari and J. Mannhart, Phys. Rev. B, 1990, 41, 4038.
10. D. Wolf and J. A. Jaszczak, J. Comput.-Aid. Mater. Des., 1993, 1, 111.
11. G. Centi, F. Trifiro, J. R. Ebner and V. M. Franchetti, Chem. Rev., 1988, 88, 55.
12. G. Centi, S. Perathoner and F. Trifiro, Res. Chem. Intermed., 1991, 15, 49.
13. H. Cordatos, T. Bunluesin, J. Stubenrauch, J. M. Vohs and R. J. Gorte, J. Phys. Chem., 1996, 100, 785.
14. D. C. Sayle, C. R. A. Catlow, M.-A. Perrin and P. Nortier, J. Phys. Chem., 1996, 100, 8940.
15. C. Hardacre, R. M. Ormerod and R. M. Lambert, J. Phys. Chem., 1994, 98, 10901.
16. S. Ramamurthy and C. B. Carter, Phys. Status Solidi A, 1998, 166, 37.
17. M. Kubo, Y. Oumi, R. Miura, A. Stirling, A. Miyamoto, M. Kawasaki, M. Yoshimoto and H. Koinuma, Phys. Rev. B, 1997, 56, 13535.
18. A. M. Stoneham, M. M. D. Ramos and A. P. Sutton, Phil. Mag. A, 1993, 67, 797.
19. S. Bernal, F. J. Botana, J. J. Calvino, G. A. Cifredo, J. A. Perez-Omil and J. M. Pintado, Catal. Today, 1995, 23, 219.
20. D. M. Lind, S. D. Berry, G. Chern, H. Mathias and L. R. Testardi, Phys. Rev. B, 1992, 45, 1838.
21. G. Chern, Surf. Sci., 1997, 387, 183.
22. G. Balducci, J. Kaspar, P. Fornasiero, M. Graziani, M. S. Islam and J. D. Gale, J. Phys. Chem. B, 1997, 101, 1750.
23. D. C. Sayle, T. X. T. Sayle, S. C. Parker, J. H. Harding and C. R. A. Catlow, Surf. Sci., 1995, 334, 170.
24. D. C. Sayle, J. Mater. Chem., 1998, 8, 2025.
25. A. L. Shluger, A. L. Rohl and D. H. Gay, Phys. Rev. B, 1995, 51, 13631; A. L. Shluger, A. L. Rohl and D. H. Gay, J. Vac. Sci. Technol. B, 1995, 13, 1190.
26. T. S. Bush, C. R. A. Catlow and P. D. Battle, J. Mater. Chem., 1995, 5, 1269.
27. D. H. Gay and A. L. Rohl, J. Chem. Soc., Faraday Trans., 1995, 91, 925.
28. N. Metropolis, A. W. Rosenbluth, M. N. Rosenbluth, A. H. Teller and E. Teller, J. Chem. Phys., 1953, 21, 1087.
29. J. Yao, R. A. Greenkorn and K. C. Chao, Mol. Phys., 1982, 46, 587.
30. J. Goniakowski and C. Noguera, Surf. Sci., 1995, 340, 191.
31. E. S. Hellman, E. H. Hartford and E. M. Gyorgy, Appl. Phys. Lett., 1991, 58, 1335.
32. E. Olsson, A. Gupta, M. D. Thouless, A. Segmuller and D. R. Clarke, Appl. Phys. Lett., 1991, 58, 1682.
33. J. M. Recio, R. Pandey, A. Ayuela and A. B. Kunz, J. Chem. Phys., 1993, 98, 4783.