Magnetic structure of ${\mathrm{GdNi}}_2$${\mathrm{B}}_2$C by resonant and nonresonant x-ray scattering

Resonant and nonresonant x-ray magnetic scattering techniques have been used to study the low-temperature magnetic structure of ${\mathrm{GdNi}}_2$${\mathrm{B}}_2$C. Taken together, these measurements allow a determination of the ordered moment direction and its evolution with temperature from a single orientation of the sample. The experimental results show that below approximately 19.4 K this compound forms an incommensurate antiferromagnetic state with a magnetic wave vector of approximately 0.55a* (b*) in the basal plane of the tetragonal structure. Between 19.4 and 13.6 K, the ordered moment is along the b (a) axis. Below approximately 13.6 K an ordered component of the moment develops along the c axis. © 1996 The American Physical Society.