  The magnetic behavior of single-crystalline CeCuGa3 has been investigated.
The compound forms in a tetragonal BaAl4-type structure consisting of
rare-earth planes separated by Cu-Ga layers. If the Cu-Ga site disorder is
reduced, CeCuGa3 adopts the related, likewise tetragonal BaNiSn3-type
structure, in which the Ce ion are surrounded by different Cu and Ga layers and
the inversion symmetry is lost. In the literature conflicting reports about the
magnetic order of CeCuGa3 have been published. Single crystals with the
centrosymmetric structure variant exhibit ferromagnetic order below approx. 4 K
with a strong planar anisotropy. The magnetic behavior above the transition
temperature can be well understood by the crystal-field splitting of the 4f
Hund's rule ground-state multiplet of the Ce ions.
