We have measured Re 5d spin and orbital magnetic moments in the ferrimagnetic
double perovskite Sr2CrReO6 by X-ray magnetic circular dichroism at the L_{2,3}
edges. In fair agreement with recent band-structure calculations [Vaitheeswaran
et. al., Ref 1], at the Re site a large 5d spin magnetic moment of -0.68 mu_B
and a considerable orbital moment of +0.25 mu_B have been detected. We found
that the Curie temperature of the double perovskites A2BB'O6 scales with the
spin magnetic moment of the 'non-magnetic' B' ion.Comment: 3 pages, 3 figure