X-ray magnetic-scattering study of magnetism in hydrogenated thin holmium films

The magnetic structure of holmium exhibits an incommensurate spin spiral be low the Neel temperature of 131.5 K. We have studied the effect of hydroge n on the magnetic properties of antiferromagnetic holmium. Combining thin-f ilm deposition techniques with resonant magnetic X-ray scattering at the Ho LIII absorption edge, we were able to follow the magnetic properties of Ho Hx, with a small X-ray beam along a lateral hydrogen gradient in the sample . The results show that the period for the spin spiral increases with incre asing hydrogen concentration while the Neel temperature decreases. Both eff ects can be related to a weakening of the RKKY interaction caused by a depl etion of the mediating conduction electrons, which fill a low-lying hydroge n band.