Title: Non-collinear antiferromagnetic structure in PrCuAl
Abstract: We report on the magnetic structure in PrCuAl as determined by powder neutron diffraction. This compound crystallizes in the hexagonal ZrNiAl-type structure and the bulk measurements indicated an antiferromagnetic order in PrCuAl below TN = 7.9 K. Our neutron-diffraction data confirmed the antiferromagnetic order below TN and revealed the propagation vector (1/3, 1/3, 1/3). The Pr magnetic moments lie within the basal plane and form a triangular structure. This magnetic structure differs from antiferromagnetic structures observed in other RCuAl or RNiAl compounds that are mostly characterized by (1/2, 0, q) propagation.