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LEEM Investigations of bcc Metals Grown Heteroepitaxially on Sapphire

Published online by Cambridge University Press:  10 February 2011

W. Swiech
Affiliation:
University of Illinois at Urbana-Champaign, 104 S. Goodwin, Urbana, IL 61801, USA
M. Ondrejcek
Affiliation:
University of Illinois at Urbana-Champaign, 104 S. Goodwin, Urbana, IL 61801, USA
R.S. Appleton
Affiliation:
University of Illinois at Urbana-Champaign, 104 S. Goodwin, Urbana, IL 61801, USA
C.S. Durfee
Affiliation:
University of Illinois at Urbana-Champaign, 104 S. Goodwin, Urbana, IL 61801, USA
M. Mundschau
Affiliation:
University of Illinois at Urbana-Champaign, 104 S. Goodwin, Urbana, IL 61801, USA
C.P. Flynn
Affiliation:
University of Illinois at Urbana-Champaign, 104 S. Goodwin, Urbana, IL 61801, USA
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Abstract

We describe studies of refractory metals Mo and Nb, grown heteroepitaxially in the (011) orientation on sapphire (1120), using low energy electron microscopy (LEEM). A wide variety of structural and dynamical phenomena are observed and recorded as video sequences. These are organized here in five categories as follows. First are surface impurity phases identified by LEED. It is an important point, established here for Mo, that almost ideally clean surfaces with mainly single stepped terraces, can be prepared on thin films for use in surface science. Second, surface reconstruction phenomena can also be identified by diffraction. This is illustrated here by a reconstruction of the Nb surface, with two equivalent domains that form a stripe phase, owing to competing long and short range interactions. Detailed studies of nucleation, fluctuations and the equilibrium of these variants are described. The third area is surface topography, illustrated here by almost ideal stepped surfaces of Mo and Nb at high temperatures, and by nanofaceting by step edge coalescence to form {110} facets on Nb at lower temperatures. The phase diagram for nanofaceting is discussed. Fourth are processes at the internal Al2O3-metal interface, as interfacial dislocations, misorientation steps and defects become visible in the LEEM image through the displacement fields they cause. The final category includes bulk process where the observed dynamics of threading screw and edge dislocations and accompanying slip traces reveal their release at high temperatures from Cottrell atmospheres. The kinetics are tracked as surface diffusion smooths dislocation slip traces, and the interactions among dislocations and surface steps are measured.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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References

1.Telieps, W. and Bauer, E., Ultramicroscopy 17, 99 (1985); L.H. Veneklasen, Rev. Sci. Instrum. 63, 5513 (1992).Google Scholar
2.Tromp, R.M. and Reuter, M.C., Ultramicroscopy 36, 99 (1991); R.M. Tromp, M. Mankos, M.C. Reuter, A.W. Ellis and M. Copel, Surf. Rev. Lett. 5, 1189 (1998).Google Scholar
3.Telieps, W., Mundschau, M. and Bauer, E., Surf. Sci. 225, 87 (1990).Google Scholar
4.Mundschau, M., Bauer, E. and Swiech, W., Phil. Mag. A 59, 217 (1989).Google Scholar
5.Altman, M.S., Surf. Sci. 344, 65 (1995).Google Scholar
6.Mundschau, M., Bauer, E., Telieps, W. and Swiech, W., Phil. Mag. A 61, 257 (1990).Google Scholar
7.Tromp, R.M. and Reuter, M.C., Phys. Rev. Lett. 68, 820 (1992).Google Scholar
8.Hannon, J.B., Bartelt, N.C., Swartzentruber, B.S., Hamilton, J.C. and Kellogg, G.L., Phys. Rev. Lett. 79, 4226 (1997).Google Scholar
9.Sutter, P., Mateeva, E., Sullivan, J.S. and Lagally, M.G., Thin Solid Films 336, 262 (1998).Google Scholar
10.Mundschau, M., Bauer, E., Telieps, W. and Swiech, W., Surf. Sci. 223, 413 (1989).Google Scholar
11.Pelhos, K., Hannon, J.B., Kellog, G.L. and Madey, T.E., Surf. Sci. 432, 115 (1999).Google Scholar
12.Meyer, F.-J.Heringdorf, zu, Kahler, D., Hoegen, M. Horn-von, Schmidt, T., Bauer, E., Copel, M. and Minoda, H., Surf. Rev. Lett. 5, 1167 (1998).Google Scholar
13.Altman, M.S. and Bauer, E., Surf. Sci. 347, 65 (1996).Google Scholar
14.Altman, M.S. and Bauer, E., Surf. Sci. 344, 51 (1995).Google Scholar
15.Bauer, E., Rep. Prog. Phys. 57, 895 (1994).Google Scholar
16.Mundschau, M., Bauer, E. and Swiech, W., Surf. Sci. 203, 412 (1988).Google Scholar
17.Tromp, R.M., Denier van der Gon, A.W., LeGoues, F.K. and Reuter, M.C., Phys. Rev. Lett. 71, 3299 (1993).Google Scholar
18.Mundschau, M., Bauer, E., Telieps, W. and Swiech, W., Surf. Sci. 213, 381 (1989).Google Scholar
19.Swiech, W., Bauer, E. and Mundschau, M., Surf. Sci. 253, 283 (1991).Google Scholar
20.Denier van der Gon, A.W., Tromp, R.M. and Reuter, M.C., Thin Solid Films 236, 140 (1993).Google Scholar
21.Durbin, S.M., Cunningham, J.A., Mochel, M.E. and Flynn, C.P., J. Phys. F 11, L223 (1981); S.M. Durbin, J.A. Cunningham, C.P. Flynn, J. Phys. F 12, L75 (1982).Google Scholar
22.Zhou, G.L., Bonham, S. and Flynn, C.P., J. Phys.: Condens. Matter 9, L671 (1997).Google Scholar
23.Flynn, C.P. and Yang, M.H. in Epitaxial Oxide Thin Films, edited by J.Speck, S., Fork, D.K., Wolf, R.M. and Shiosaki, T. (Mater. Res. Soc. Proc. 401, Pittsburgh, PA, 1996) p. 1.Google Scholar
24.Huth, M. and Flynn, C.P., J. Appl. Phys. 83, 7261 (1998).Google Scholar
25.Flynn, C.P. and Salamon, M.B., in Handbook of Physics and Chemistry of Rare Earths, Vol. 22, edited by Gschneider, K. and Eyring, L., (Elsevier, Amsterdam, 1996), p. 1.Google Scholar
26.Swiech, W., Mundschau, M. and Flynn, C.P., Surf. Sci. 437, 61 (1999).Google Scholar
27.Haas, T.W. and Grant, J.T., Appl. Phys. Lett. 16, 172 (1970).Google Scholar
28.Haas, T.W., Grant, J.T. and Dooley, G.J. III, J. Appl. Phys. 43, 1853 (1973).Google Scholar
29.Bauer, E. and Poppa, H., Surf. Sci. 127, 243 (1983).Google Scholar
30.Pantel, R., Bujor, M. and Bardolle, J., Surf. Sci. 62, 589 (1977).Google Scholar
31.Franchy, R., Bartke, T.U. and Gassmann, P., Surf. Sci. 366, 60 (1996).Google Scholar
32.Huebener, R.P., Magnetic Flux Structures in Superconductors, (Springer, Berlin, 1979).Google Scholar
33.Bartelt, N.C. and Tromp, R.M., Phys. Rev. B 54, 11731 (1996).Google Scholar
34.Bartelt, N.C., Goldberg, J.L., Einstein, T.L., Williams, E.D., Heyraud, J.C. and Métois, J.J., Phys. Rev. B 48, 15453 (1993).Google Scholar
35.Seul, M. and Andelman, D., Science 267, 476 (1995).Google Scholar
36.Vitas, L., Ruban, A.V., Skriver, H.L. and Kollar, J., Surf. Sci. 411, 186 (1998).Google Scholar
37.Flynn, C.P., Swiech, W., Appleton, R.S. and Ondrejcek, M., Phys. Rev. B (in press).Google Scholar
38.Flynn, C.P. and Swiech, W., Phys. Rev. Lett. 83, 3482 (1999).Google Scholar
39.Swiech, W., Mundschau, M. and Flynn, C.P., Appl. Phys. Lett. 74, 2626 (1999).Google Scholar
40.Mundschau, M., Swiech, W., Durfee, C.S. and Flynn, C.P., Surf. Sci. Lett. 440, L831 (1999).Google Scholar