# Bulk single crystal growth of the theoretically predicted magnetic Weyl semimetals $R$AlGe ($R$ = Pr, Ce)

## TL;DR

This study develops a crucible-free floating zone method for growing high-quality single crystals of magnetic Weyl semimetals RAlGe (R=Pr,Ce), revealing their actual magnetic properties and structural details.

## Contribution

It introduces a flux-free crystal growth technique for RAlGe, enabling accurate structural and magnetic characterization of these topological materials.

## Key findings

- Floating zone growth yields stoichiometric RAlGe crystals.
- PrAlGe shows spin-glass-like transition below 16 K.
- CeAlGe exhibits antiferromagnetic order below 5 K.

## Abstract

We explore two methods for single crystal growth of the theoretically proposed magnetic Weyl semimetals $R$AlGe ($R$ = Pr,Ce), which prove that a floating zone technique, being both crucible- and flux-free, is crucial to obtain perfectly stoichiometric $R$AlGe crystals. In contrast, the crystals grown by a flux growth technique tend to be Al-rich. We further present both structural and elemental analysis, 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 I4$_{1}$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.