Characterization of soft magnetic nanocomposites
Optimizing the performance of soft magnetic materials requires an understanding of the nanostructure and consideration of the local composition of each phase. The researchers successfully correlated the crystallization state in the alloy to local composition with novel mass balance. The alloy of composition (Fe65Co35)79.5B13Si2Nb4Cu1.5 was synthesized and subsequently heat-treated by the research group of Professor Michael McHenry of Carnegie Mellon University. Atom probe tomography (APT) was then used to characterize the various stages of crystallization in EMSL, the Environmental Molecular Sciences Laboratory. APT produced 3-D atom maps of all alloy constituents (shown in the IEEE Transactions on Magnetics cover). The local concentrations of elements obtained through APT were then used in mass balances (quantifying the glass formers in nanocrystals, enrichment of glass formers, and depletion of iron and cobalt in the amorphous phase).