Magnetic structure of GdCo2Ge2 -: art. no. 224427

Resonant and nonresonant magnetic x-ray scattering studies of GdCo2Ge2 were performed to determine its magnetic structure at low temperature. This compound orders in an incommensurate antiferromagnetic (AF) structure characterized by a propagation wave vector tau=(0 0 tau(z)). The value of tau(z) is temperature dependent and approaches 0.930 reciprocal lattice units well below T-N=33.25 K. A peak corresponding to 3 tau(z) was also observed, indicating either a squaring up of the magnetic structure or the presence of a noncollinear amplitude modulated structure below T-N. Fitting the angular dependence of the magnetic scattering integrated intensities to the relevant resonant and nonresonant scattering cross sections revealed that the moment direction lies primarily in the tetragonal basal plane. Scattering measurements at the Co K- edge failed to detect any resonant signal, consistent with the absence of a magnetic moment on the Co sites.