The relationships between microstructure, controlled by alloying elements prone to grain boundary segregation, and electrical resistivity in sputtered nanocrystalline Cu were investigated. We find a non-monotonic dependence of the mean grain size on solute concentration for both Cu-Nb and Cu-Fe dilute alloys, with a concentration regime where the grain size increases over that of pure Cu before refining with further alloying. The electrical resistivity follows the same trend, suggesting a non-equilibrium processing route that remarkably gives rise to dilute nanocrystalline Cu alloys with lower resistivity, thermal stability, and enhanced mechanical properties relative to their pure nanocrystalline counterpart. Nanocrystalline (NC) metals have been the subject of intense research activity, driven largely by technological interests in their high hardness and strength. The results from decades of experiments and simulations point to the governing role of deformation physics unique to its coarse-grained counterparts, including grain boundary (GB) sliding, nucleation of dislocations from GBs and their subsequent isolated propagation, GB rotation, and stress-assisted grain growth [1,2]. Owing to the large volume fraction of material in near-GB regions in nanocrystalline metals, the properties of these materials are governed by interfacial phenomena.
ABSTRACT Evolution of magnetic interaction has been investigated in Co/Pd multilayer films with 5, 9 and 15 repeats. All these samples were characterized by Isothermal remanence magnetization (IRM), DC demagnetization (DCD) and first order reversal curve (FORC). The δM plots obtained from the IRM and DCD data indicate exchanging coupling evolves into magnetostatic interaction as the repeat increases from 5 to 15. The FORC measurement was used to confirm this evolution and the FORC diagrams exhibit the effect of magnetic interaction on the reversal mechanism.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.