Exchange springs in antiferromagnetically coupled DyFe2-YFe2 superlattices

Molecular beam epitaxy methods have been used to grow single-crystal Laves phase DyFe2-YFe2, superlattice samples with a (110) growth direction. In this paper, magnetization curves for the multilayer samples [wDyFe(2)/wYFe(2)] x 40, with w = 50, 75, 100, 150, and 300 Angstrom, are presented and discussed. Below T-C, the magnetic moments of the DyFe2 layers are coupled antiferromagnetically to those of the YFe2 layers. However, in applied fields, it is possible to generate magnetic exchange springs in the YFe2 layers, with well-defined bending (onset) fields B-B. In particular, it is demonstrated, both experimentally and theoretically, that the bending field B-B is closely proportional to 1/w(2), where w is the thickness of the magnetically soft YFe2 layer.