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

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.

6 pages, 6 figures accepted for publication in Physical Review Materials

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Cited by in corpus (1)

• Honeycomb lattice in metal-rich chalcogenide Fe2Te