Magnetic Structure of DyC2

Abstract

The compound, DyC₂, having the tetragonal body‐centered CaC₂‐type structure has been shown by neutron diffraction to exhibit the magnetic spin alignment of a linear, transverse wave mode below the Néel temperature of 59°K. This static moment wave is propagating along the $a$ axis and is polarized in the c‐axis direction. The root‐mean‐square and maximum saturation moments per Dy are 8.37 and 11.8 Bohr magnetons, respectively, the latter being considerably larger than the ordered moment of the free Dy^3 + ion, 10.0 ${\mu }_B$ . The wavelength of the moment wave is about 1.3 times the $a$ spacing and is practically temperature independent. An additional, coexisting spin alignment with a very small moment appears to take place below 31°K. The crystallographic parameters in the range 300°–5°K are also presented. The thermal‐neutron coherent scattering amplitude of Dy is established as (1.70 ± 0.01) × 10^− 12 cm.