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arXiv · 2002.09507

Molecular beam epitaxy preparation and in situ characterization of FeTe thin films

V. M. Pereira·C. N. Wu·C. E. Liu·S. -S. Liao·C. F. Chang·C. -Y. Kuo·C. Koz·U. Schwarz·H. -J. Lin·C. T. Chen. L. H. Tjeng·S. G. Altendorf
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Abstract

We have synthesized Fe$_{1+y}$Te thin films by means of molecular beam epitaxy (MBE) under Te-limited growth conditions. We found that epitaxial layer-by-layer growth is possible for a wide range of excess Fe values, wider than expected from what is known on the bulk material. Using x-ray magnetic circular dichroism spectroscopy at the Fe L$_{2,3}$ and Te M$_{4,5}$ edges, we observed that films with high excess Fe contain ferromagnetic clusters while films with lower excess Fe remain nonmagnetic. Moreover, x-ray absorption spectroscopy showed that it is possible to obtain films with very similar electronic structure as that of a high quality bulk single crystal Fe$_{1.14}$Te. Our results suggest that MBE with Te-limited growth may provide an opportunity to synthesize FeTe films with smaller amounts of excess Fe as to come closer to a possible superconducting phase.

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V. M. Pereira, C. N. Wu, C. E. Liu, S. -S. Liao, C. F. Chang, C. -Y. Kuo, C. Koz, U. Schwarz, H. -J. Lin, C. T. Chen. L. H. Tjeng, S. G. Altendorf. 2020-02-21. Molecular beam epitaxy preparation and in situ characterization of FeTe thin films. https://doi.org/10.1103/physrevmaterials.4.023405

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