Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-10T08:53:03.428Z Has data issue: false hasContentIssue false

X-Ray Photoelectron and Auger Electron Forward-Scattering Studies of the Epitaxial Growth of Fe on Ag(100).

Published online by Cambridge University Press:  15 February 2011

William F. Egelhoff Jr.*
Affiliation:
Surface & Microanalysis Science Division National Institute of Standards and Technology Gaithersburg, MD 20899
Get access

Abstract

A controversy has arisen in the past year over whether or not the growth of Fe on Ag(100) at room temperature occurs by a layer-by-layer mechanism. The present work attempts to address this controversy with an investigation of the issues, primarily by x-ray photoelectron (XPS) and Auger electron forward scattering, but with important supporting data from low-energy electron diffraction (LEED), and reflection high-energy electron diffraction (RHEED) oscillations. The results of this work suggest that the origin of the controversy lies in different substrate preparation techniques which produce different atomic step densities on the Ag(100) surface. The step sites are implicated as being the initiators of major departures from a layer-by-layer growth mode whenever most of the deposited Fe atoms have sufficient mobility to reach these steps. However, even when the Fe atoms cannot reach these steps it appears that atomic place-exchange occurs with ≥25% of the top-layer Ag atoms. Atomic place-exchange mechanisms, which could account for this intermixing, have been observed in recent molecular-dynamics simulations of epitakial growth. Thus it seems probable that under the conditions that appear to produce layer-by-layer growth, the growth begins as layer-by-layer growth of an FeAg alloy, and only becomes layer-by-layer in pure Fe as the segregating Ag atoms gradually get left behind in the growing Fe film.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Smith, G.C., Padmore, G.A., and Norris, C., Surface Sci. 119, L287 (1982).Google Scholar
[2] Richter, R., Gay, J.G., and Smith, J.R., J. Vac. Sci. Technol. A3, 1498 (1984).Google Scholar
[3] Fu, C.L., Freeman, A.J., and Oguchi, T., Phys. Rev. Lett. 54, 2700 (1985).CrossRefGoogle Scholar
[4] Richter, R., Gay, J.G., and Smith, J.R., Phys. Rev. Lett. 54, 2704 (1985).Google Scholar
[5] Jonker, B.T., Walker, K.-H., Kisker, E., Prinz, G.A., and Carbone, C., Phys. Rev. Lett. 57, 142 (1986).CrossRefGoogle Scholar
[6] Jonker, B.T. and Prinz, G.A., Surface Sci. 172, L568 (1986).Google Scholar
[7] Heinrich, B., Urquhart, K.B., Arrott, A.S., Cochran, J.F., Myrtle, K., and Purcell, S.T., Phys. Rev. Lett. 59, 1756 (1987).CrossRefGoogle Scholar
[8] Jonker, B.T., Prinz, G.A., Kisker, E., Walker, K.-H., and Carbone, C., J. Appl. Phys. 61, 3366 (1987).CrossRefGoogle Scholar
[9] Gay, J.G. and Richter, R., J. Appl. Phys. 61, 3362 (1987). 39Google Scholar
[10] Koon, N.C., Jonker, B.T., Volkening, F.A., Krebs, J.J., and Prinz, G.A., Phys. Rev. Lett. 59. 2463 (1987).Google Scholar
[11] Stampanoni, M., Vaterlaus, A., Aeschlimann, M., and Meier, F., Phys. Rev. Lett. 59. 2483 (1987).Google Scholar
[12] Urquhart, K.B., Heinrich, B., Cochran, J.F., Arrott, A.S., and Myrtle, K., J. Appl Phys. 64, 5334 (1988).Google Scholar
[13] Heinrich, B., Urquhart, K.B., Dutcher, J.R., Purcell, S.T., Cochran, J.F., Arrott, A.S., Steigerwald, D.A., and Egelhoff, W.F. Jr., J. Appl. Phys. 63, 3863 (1988).Google Scholar
[14] Vaterlaus, A., Stampanoni, M., Aeschlimann, M., and Meier, F., J. Appl. Phys. 64, 5331 (1988).Google Scholar
[15] Robins, J.L., Celotta, R.J., Unguris, J., and Pierce, D.T., Appl. Phys. Lett. 52, 1918 (1988).Google Scholar
[16] Schneider, C. M., de Miguel, J.J., Bressler, P., Garbe, J., Ferrer, S., Miranda, R., and Kirschner, J., J. Phys. Colloq. (Paris) 49, C81657 (1988).CrossRefGoogle Scholar
[17] Heinrich, B., Purcell, S.T., Dutcher, J.R., Urquhart, K.B., Cochran, J.F., and Arrott, A.S., Phys. Rev. B 38, 12879 (1988).Google Scholar
[18] Heinrich, B., Cochran, J.F., Arrott, A.S., Urquhart, K.B., Myrtle, K., Celinski, Z., and Zhong, Q.-M., Mat. Res. Soc. Symp. Proc. 151, 177 (1989).Google Scholar
[19] Rau, C., Appl. Phys. A 49, 579 (1989).Google Scholar
[20] Egelhoff, W.F. Jr. and Jacob, I., Phys. Rev. Lett. 62, 921 (1989).CrossRefGoogle Scholar
[21] Krebs, J.J., Jonker, B.T., and Prinz, G.A., Mat. Res. Soc. Symp. Proc. 151, 23 (1989).Google Scholar
[22] Ballentine, C.A., Fink, R.L., Araya-Pochet, J., and Erskine, J.L., Appl. Phys. A 49, 459 (1989).Google Scholar
[23] Stampanoni, M., Appl. Phys. A49, 449 (1989).Google Scholar
[24] Heinrich, B., Cochran, J.F., Arrott, A.S., Purcell, S.T., Urquhart, K.B., Dutcher, J.R., and Egelhoff, W.F. Jr., Appl. Phys. A 49, 473 (1989).Google Scholar
[25] Li, H. and Tonner, B.P., Phys. Rev. B 40, 10241 (1989).Google Scholar
[26] Krebs, J.J., Appl. Phys. A 49, 513 (1989).Google Scholar
[27] Purcell, S.T., Ph. D. Thesis, Simon Fraser Univ., 1989.Google Scholar
[28] Urquhart, K.B., Ph. D. Thesis, Simon Fraser Univ., 1989.Google Scholar
[29] Myrtle, K., Ph. D. Thesis, Simon Fraser Univ., 1989.Google Scholar
[30] Bland, J.A.C., Johnson, A.D., Norris, C., and Lauter, H.J., J. Appl. Phys. 67, 5397 (1990).CrossRefGoogle Scholar
[31] Etienne, P., Lequien, S., Nguyen-Van-Dau, F., Cabanel, R., Creuzet, G., Friederich, A., Massies, J., Fert, A., Barthélémy, A., and Petroff, F., J. Appl. Phys. 67, 5400 (1990).Google Scholar
[32] Cabanel, R., Etienne, P., Lequien, S., Creuzet, G., Barthélémy, A., and Fert, A., J. Appl. Phys. 67, 5409 (1990).CrossRefGoogle Scholar
[33] Gutierrez, C.J., Qiu, Z.Q., Wieczorek, M.D., and Walker, J.C., J. Appl. Phys. 67, 5415 (1990).CrossRefGoogle Scholar
[34] Li, C., Freeman, A.J., Jansen, H.J.F., and Fu, C.L., Phys. Rev. B42, 5433 (1990).Google Scholar
[35] Rau, C., Jin, C., and Xing, G., Phys. Lett. A144, 406 (1990).CrossRefGoogle Scholar
[36a] Li, H., Li, Y.S., Quinn, J., Tian, D., Sololov, J., Jona, F., and Marcus, P.M., Phys. Rev. B42, 9195 (1990).CrossRefGoogle Scholar
[36b] Heinrich, B. and Arrott, A.S., to be published.Google Scholar
[37] Fadley, C.S., Phys. Scr. T17, 39 (1987).CrossRefGoogle Scholar
[38] Egelhoff, W.F. Jr., CRC Crit. Rev. Sol. St. & Mat. Sci. 16, 213 (1990).Google Scholar
[39] Chambers, S.A., Adv. Phys, in press, 1991.Google Scholar
[40] Egelhoff, W.F. Jr., Jacob, I., Rudd, J.M., Cochran, J.F., and Heinrich, B., J. Vac. Sci. Technol. A8, 1582 (1990).Google Scholar
[41] Egelhoff, W.F. Jr. Mat. Res. Soc. Symp. Proc. 37, 443 (1985).Google Scholar
[42] Egelhoff, W.F. Jr. Mat. Res. Soc. Symp. Proc. 83, 189 (1987).Google Scholar
[43] Steigerwald, D.A., Jacob, I., and Egelhoff, W.F. Jr., Surface Sci. 202, 472 (1988).Google Scholar
[44] Steigerwald, D.A. and Egelhoff, W.F. Jr., J. Vac. Sci. Technol. A7, 3123 (1989)Google Scholar
[45] Smith, J.R. and Banerjea, A., Phys. Rev. Lett. 59, 2451 (1987).Google Scholar
[46] There being no experimental values available, the Fe/Ag(100) interfacial free energy is best estimated by recognizing that at the interface each Fe atom has 4 Fe and 4 Ag nearest neighbors and each Ag atom 4 Fe and 8 Ag nearest neighbors. The interfacial free energy is then estimated by averaging the heat of formation of FeAg and FeAg2 alloys, with these values being taken from: deBoer, F.R., Boom, R., Mattens, W.C.M., Miedema, A.R., Niessen, A.K., Cohesion in Metals, North-Holland, Amsterdam, 1988, p. 224.Google Scholar
[47] Bader, S.D. and Moog, E.R., J. Appl. Phys. 61, 3729 (1987).Google Scholar
[48] Schmitz, P.J., Leung, W.-Y., Graham, G.W., and Theil, P.A., Phys. Rev. B40, 11477 (1989).Google Scholar
[49] Tobin, J.G., Hansen, J.C., and Wagner, M.K., J. Vac. Sci. Technol. A8, 2494 (1990).CrossRefGoogle Scholar
[50] Tobin, J.G., Wagner, M.K., Guo, X.-Q., and Tong, S.Y., Mat. Res. Soc. Proc., in press, 1991.Google Scholar
[51] Calculated using phase shifts from Fink, M. and Ingram, J., Atomic Data 4, 1 (1972). Note that the wave backscattered by the Ag atom will forward scatter on its way through the Fe atom and pick up a small phase shift which will slightly modify the energies, quoted above, at which constructive and destructive interferences occur.Google Scholar
[52] Raeker, T.J., Sanders, D.E., and DePristo, A.E., J. Vac. Sci. Technol. A8, 3531 (1990).Google Scholar
[53] Feibelman, P.J., Phys. Rev. Lett. 65, 729 (1990).Google Scholar
[54] Chen, C. and Tsong, T.T., Phys. Rev. Lett. 64, 3147 (1990).Google Scholar
[55] Kellogg, G.L. and Feibelman, P.J., Phys. Rev. Lett. 64, 3143 (1990).Google Scholar
[56] Wrigley, J.D. and Ehrlich, G., Phys. Rev. Lett. 44, 661 (1980); See also, related work in: D.W. Bassett and P.R. Webber, Surface Sci. 70, 520 (1978).Google Scholar
[57] Lutke, D. and Landman, U., to be published.Google Scholar
[58] See pp. 298 and 462 in deBoer, op. cit., Ref. 46.Google Scholar
[59] See, for example, Jaklevic, R.C. and Elie, L., Phys. Rev. Lett. 60, 120 (1988).Google Scholar