Paul, A.; Teichert, A.; Krist, T.; Steitz, R.: Substrate-stress-induced magnetic and nonmagnetic structural correlations in Fe/Si multilayers. Journal of Applied Crystallography 48 (2015), p. 1023-1033
Application of a bias voltage can influence the growth kinetics and thereby the stress in a magnetic multilayer. The inherent structural correlations in turn can influence the magnetic domain structures and thereby the overall device performance. Here, prototypical Fe/Si supermirrors are subjected to stress relaxation during the growth of sequential layers by applying a sufficient substrate bias voltage. A change in the coercivity associated with the grain size variation upon biasing is found. Most interestingly, using polarized neutron scattering, it is possible to identify that the conformal roughness becomes nonconformal with the relaxation of stress within the multilayers. The magnetic domains, on the other hand, always remain nonconformal (independent of the structural change) as they undergo spatial fluctuations around a mean magnetization. This study underscores the importance of the substrate biasing in affecting the structural correlation, which is detrimental to the resultant optical (e.g. supermirror) quality.