The electronic, magnetic, thermoelectric, and topological properties of Heusler compounds (composition XYZ or X2YZ) are highly sensitive to stoichiometry and defects. Here we establish the existence and experimentally map the bounds of a \textit{semi} adsorption-controlled growth window for semiconducting half Heusler FeVSb films, grown by molecular beam epitaxy (MBE). We show that due to the high volatility of Sb, the Sb stoichiometry is self-limiting for a finite range of growth temperatures and Sb fluxes, similar to the growth of III-V semiconductors such as GaSb and GaAs. Films grown within this window are nearly structurally indistinguishable by X-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED). The highest electron mobility and lowest background carrier density are obtained towards the Sb-rich bound of the window, suggesting that Sb-vacancies may be a common defect. Similar \textit{semi} adsorption-controlled bounds are expected for other ternary intermetallics that contain a volatile species Z=\{Sb, As, Bi\}, e.g., CoTiSb, LuPtSb, GdPtBi, and NiMnSb. However, outstanding challenges remain in controlling the remaining Fe/V (X/Y) transition metal stoichiometry.
@article{arxiv.2003.05971,
title = {Semi-adsorption-controlled growth window for half Heusler FeVSb epitaxial films},
author = {Estiaque H. Shourov and Ryan Jacobs and Wyatt A. Behn and Zachary J. Krebs and Chenyu Zhang and Patrick J. Strohbeen and Dongxue Du and Paul M. Voyles and Victor W. Brar and Dane D. Morgan and Jason K. Kawasaki},
journal= {arXiv preprint arXiv:2003.05971},
year = {2020}
}