Absence of superconductivity in topological metal ScInAu${}_2$

The Heusler compound ScInAu${}_2$ was previously reported to have a superconducting ground state with a critical temperature of 3.0 K. Recent high throughput calculations have also predicted that the material harbors a topologically non-trivial band structure similar to that reported for beta-PdBi${}_2$. In an effort to explore the interplay between the superconducting and topological properties properties, electrical resistance, magnetization, and x-ray diffraction measurements were performed on polycrystalline ScInAu${}_2$. The data reveal that high-quality polycrystalline samples lack the super-conducting transition present samples that have not been annealed. These results indicate the earlier reported superconductivity is non-intrinsic. Several compounds in the Au-In-Sc ternary phase space (ScAu${}_2$, ScIn${}_3$, and ScInAu${}_2$) were explored in an attempt to identify the secondary phase responsible for the non-intrinsic superconductivity. The results suggest that elemental In is responsible for the reported superconductivity in ScInAu${}_2$.