Dresden 2006 – wissenschaftliches Programm

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O: Oberflächenphysik

O 20: Epitaxy and growth II

O 20.4: Vortrag

Dienstag, 28. März 2006, 12:00–12:15, WIL B321

Epitaxial growth of thin Fe-films on GaAs(110) at 80K — •L. Winking, M. Wenderoth, J. Homoth, and R. G. Ulbrich — Universität Göttingen, IV. Physikalisches Institut

The best conditions for the eptiaxial growth of Fe on GaAs(001) or GaAs(110) were reported to be at substrate temperatures of about 175^∘C [1]. Nevertheless the highest spin injection efficiencies were reported for films grown at 10-15^∘C, due to the reduced intermixing at the Fe/GaAs heterointerface [2]. At lower substrate temperatures Fe films showed an increasing number of defects towards a nanoclustered film.

We present a combined LEED and STM study of thin Fe films that were deposited at 80K on in-situ cleaved GaAs(110). The film thickness ranges from a sub-monolayer coverage up to several monolayers. After annealing to RT Fe films of more than 3 ML thickness show the well known LEED pattern of Fe(110) and demonstrate the good epitaxial quality of the film. STM topographies of these annealed films show clear evidence for a 2D layer-by-layer growth, in contrast to the well known 3D cluster growth of thin Fe films deposited at RT or above. Our study demonstrates that low temperature deposition of Fe on GaAs leads to thin epitaxial films of good quality. Due to the low substrate temperature the described preparation scheme may be a key technique to suppress intermixing at the Fe/GaAs heterointerface.

This work was supported by the SFB 602 TP A7.

[1] P. M. Thibado et al., PRB 53, R10481 (1996)

[2] A. T. Hanbicki et al., APL 80, 1240 (2002)