Neutron scattering study of magnetic order in single-crystalline CeCuAl3

The Ce T X₃ compounds belong to the intensively studied group of materials revealing such properties as valence fluctuations, heavy-fermion behavior, or pressure-induced superconductivity. So far, magnetic structure was investigated in only a few of these. We performed a series of neutron-diffraction experiments on a structurally well-defined CeCuAl₃ single crystal. The ordered non-centro-symmetric tetragonal BaNiSn₃-type (I4mm) crystal structure as well as the antiferromagnetic order below T_N≈2.7 K were corroborated by our diffraction experiments. The amplitude modulated magnetic structure with in-plane magnetic moments described by the propagation vector k =(0.4 ,0.6 ,0 ) was revealed. The relation between structural parameters and magnetic structures in the family of isostructural Ce T X₃ compounds is discussed.