ISIS Neutron and Muon Source Data Journal

Single Crystal Neutron Diffraction study of Weyl semimetal candidate CeGaGe

Abstract: CeGaGe belongs to the RXY (R = rare-earth; X, Y = Al, Ga, Si, Ge) family of non-centrosymmetric (NC) tetragonal compounds hosting Weyl semimetal physics, anomalous Hall effects, and topological Hall effects tied to magnetic order. Unlike related members crystallizing in space group I4_1md, CeGaGe adopts the chiral P4_3 structure while retaining select Weyl node crossings, making it a unique platform to probe topology across a structural transition. CeGaGe orders magnetically at T_ord = 4.8 K with a ground state that defies simple classification: susceptibility shows antiferromagnetic-like field suppression of T_ord, yet ZFC/FC splitting, easy-axis hysteresis, canted M(H) behavior, and a spontaneous Hall effect at 1.8 K collectively indicate a non-collinear or canted spin arrangement, likely stabilized by Dzyaloshinskii Moriya interactions permitted by the NC structure. Intrinsic anomalous Hall contributions appear only below T_ord, suggesting that magnetic order directly gates the topological state. Determining the magnetic structure is essential for connecting topology to magnetism in this distinct structural framework and for providing input to sorely needed band structure calculations. We propose single-crystal neutron diffraction on SXD, whose Laue geometry and wide simultaneous reciprocal-space coverage are ideal for indexing magnetic superlattice reflections in this low-symmetry tetragonal crystal, particularly given the potential for incommensurate or multi-k ordering.

Principal Investigator: Dr Steven Gomez Alvarado
Experimenter: Professor Pengcheng Dai
Experimenter: Miss Kaitlin McAllister
Local Contact: Dr Matthias Gutmann

DOI: 10.5286/ISIS.E.RB2620320

ISIS Experiment Number: RB2620320

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Dr Steven Gomez Alvarado et al; (2026): Single Crystal Neutron Diffraction study of Weyl semimetal candidate CeGaGe, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2620320

Data is released under the CC-BY-4.0 license.