An expedition through the intermetallic mountains: Designing a new flux growth for the kagome metal Ni₃In

Single crystal samples are essential for investigating quantum materials. One way to grow them is by slowly cooling a saturated melt to precipitate crystals in a process called flux growth. Often, this simply involves identifying a low melting point element to dissolve a little bit of your target compound. However, this approach can be hindered by competing phases, solubility issues, undersized crystals, and unintended chemical substitutions.

An alternative approach is to develop more complex fluxes to facilitate crystal growth. In this case, the solvent solution is comprised of several principal elements. This path is more challenging, requiring us to navigate an uncharted landscape in composition space. We must search the mountains and valleys that represent the solidification temperature surface to pinpoint the composition and conditions to obtain our target compound.

In this talk I will recount one expedition through an underexplored composition-temperature landscape, detailing how we developed an unconventional melt composition to grow larger single crystals of Ni₃In. This kagome metal has attracted attention because its physics lie at the cusp of order, generating strange metal behavior. I will describe the rationale behind our development of a surprisingly nickel-rich flux composition we identified by exploring eutectic valleys and avoiding competing compounds. Finally, I will compare the properties of our new Ni₃In crystals with those created by existing techniques. I will demonstrate that a well-planned expedition through composition space can uncover new routes to hard-to-make quantum materials.