Exchange springs in YFe2 dominated DyFe2–YFe2 superlattices

MBE methods have been used to grow single–crystal Laves–phase DyFe2–YFe2 superlattice samples with a (1 1 0) growth direction. In this paper, magnetisation curves for the YFe2 dominated multilayer samples [wDyFe2/4wYFe2]×N, where w=20, 30, 40, and 50 A, and N=40, 27, 20, and 16, respectively, are presented and discussed. It will be shown that the measured M–H loops are dominated by magnetic exchange springs, which reduce the magnetic coercivity, considerably. In particular, it is possible to engineer samples with a negative coercivity.