We explore two methods for single-crystal growth of the theoretically proposed magnetic Weyl semimetals $R\mathrm{AlGe}$ ($R$ = Pr, Ce), which prove that a floating-zone technique, being both crucible- and flux-free, is crucial to obtain perfectly stoichiometric $R\mathrm{AlGe}$ crystals. In contrast, the crystals grown by a flux-growth technique tend to be Al-rich. We further present both structural and elemental analyses, along with bulk magnetization and electrical resistivity data on the crystals prepared by the floating-zone technique. Both systems with the intended 1:1:1 stoichiometry crystallize in the anticipated polar $I{4}_{1}md$ (No. 109) space group, although neither displays the theoretically expected ferromagnetic ground state. Instead PrAlGe displays a spin-glass-like transition below 16 K with an easy $c$ axis and CeAlGe has an easy-$ab$-plane antiferromagnetic order below 5 K. The grown crystals provide an ideal platform for microscopic studies of the magnetic field-tunable correlation physics involving magnetism and topological Weyl nodes.

• Received 15 November 2018

DOI:https://doi.org/10.1103/PhysRevMaterials.3.024204