We report the epitaxial stabilization of GdAuSb films and GdAuSb/LaAuSb superlattices via molecular beam epitaxy on (0001)-oriented Al2O3 substrates. GdAuSb crystallize in the Au-Au dimerized YPtAs structure type (space group P63/mmc), the same structure as the Dirac semimetal LaAuSb. Angle-resolved photoemission spectroscopy (ARPES) measurements show similar near EF bandstructures for GdAuSb and LaAuSb, plus a rigid band shift for GdAuSb towards more hole-like behavior and core-like Gd 4f states ∼9~eV below the Fermi energy. LaAuSb/GdAuSb superlattices exhibit sharp superlattice fringes by X-ray diffraction and atomically-precise interfaces by scanning transmission electron microscopy. Superlattices display two transitions in temperature-dependent resistvity, compared to a single N\'{e}el temperature for thick GdAuSb films. Superlattices of LnAuSb materials (Ln= rare earth) with atomically abrupt interfaces offer a new epitaxial platform for control of magnetic and topological order via tunable intralayer exchange and reduced dimensionality.
@article{arxiv.2603.06500,
title = {Epitaxial stabilization of magnetic GdAuSb/LaAuSb superlattices},
author = {Patrick J. Strohbeen and Soohyun Im and Tamalika Samanta and Zachary LaDuca and Dongxue Du and Estiaque H. Shourov and Jessica L. McChesney and Fanny Rodolakis and Paul M. Voyles and Jason K. Kawasaki},
journal= {arXiv preprint arXiv:2603.06500},
year = {2026}
}