Hard X-ray MCD in GdNi5 and TbNi5 single crystals

XMCD experiments have been performed at the R L-2,L-3 and Ni K-edges on mag netically saturated single crystals of GdNi5 and TbNi5 ferromagnetic compou nds. The spectra present huge and well structured dichroic signals at both the R L-2,L-3 and the Ni Kedges. Structures from the quadrupolar (2p --> 4f ) transitions are clearly observed at the R L-2,L-3-edges. Though Ni is not magnetic, large intensities, up to 0.4%, are measured at the Ni K-edge. Th e Ni K-edge XMCD shows a three-peak structure which intensities dependent o n the rare earth.