High-entropy alloys(HEAs)have attracted great attention due to their many unique properties and potential applications.The nature of interatomic interactions in this unique class of complex multicomponent alloys is no...High-entropy alloys(HEAs)have attracted great attention due to their many unique properties and potential applications.The nature of interatomic interactions in this unique class of complex multicomponent alloys is not fully developed or understood.We report a theoretical modeling technique to enable in-depth analysis of their electronic structures and interatomic bonding,and predict HEA properties based on the use of the quantum mechanical metrics,the total bond order density(TBOD)and the partial bond order density(PBOD).Application to 13 biocompatible multicomponent HEAs yields many new and insightful results,including the inadequacy of using the valence electron count,quantification of large lattice distortion,validation of mechanical properties with experiment data,modeling porosity to reduce Young’s modulus.This work outlines a road map for the rational design of HEAs for biomedical applications.展开更多
Ternary FeCoNi metallic nanostructures have attracted significant attention due to their high saturation magnetization, unique mechanical properties, and large corrosion resistance. In this study, we report a controll...Ternary FeCoNi metallic nanostructures have attracted significant attention due to their high saturation magnetization, unique mechanical properties, and large corrosion resistance. In this study, we report a controlled synthesis of ternary FeCoNi nanocrystals using solution-based epitaxial core-shell nanotechnology. The thickness and stoichiometry of the FeCoNi nanocrystals affect their magnetic characteristics, which can be controlled by a phase transformation-induced tetragonal distortion. Furthermore, surface oxidation of the stoichiometry-controlled FeCoNi nanostructures can drastically enhance their magnetic coercivity （up to 8,881.60e for AuCu-FeCo）, and optimize the AuCu-FeCo08Ni0.2 performance corresponding to the saturated magnetization of 134.4 emu-g-1 and coercivity of 4,036.70e, which opens the possibility of developing rare-earth free high energy nanomagnets.展开更多
基金This research used the resources of the National Energy Research Scientific Computing Center supported by DOE under Contract No.DE-AC03-76SF00098 and the Research Computing Support Services(RCSS)of the University of Missouri SystemThe project is partially supported by DOE-NETL grant DE-FE0031554(R.S.and W.-Y.C.)+3 种基金S.S.was supported in part from funds provided by the University of Missouri-Kansas City,School of Graduate StudiesP.K.L.is supported by the National Science Foundation(DMR-1611180 and 1809640)Department of Energy(FE0008855 and DE-FE-0011194)with DrsJ.Mullen,V.Cedro,R.Dunst,S.Markovich,G.Shiflet,and D.Farkas as program managers and the U.S.Army Office Project(W911NF-13-1-0438 and W911NF-19-2-0049)with the program managers,Drs.M.P.Bakas,S.N.Mathaudhu,and D.M.Stepp.
文摘High-entropy alloys(HEAs)have attracted great attention due to their many unique properties and potential applications.The nature of interatomic interactions in this unique class of complex multicomponent alloys is not fully developed or understood.We report a theoretical modeling technique to enable in-depth analysis of their electronic structures and interatomic bonding,and predict HEA properties based on the use of the quantum mechanical metrics,the total bond order density(TBOD)and the partial bond order density(PBOD).Application to 13 biocompatible multicomponent HEAs yields many new and insightful results,including the inadequacy of using the valence electron count,quantification of large lattice distortion,validation of mechanical properties with experiment data,modeling porosity to reduce Young’s modulus.This work outlines a road map for the rational design of HEAs for biomedical applications.
基金S. R. thanks the financial support from the U.S. National Science Foundation （NSF） （No. NSF-DMR-1551948） （magnetically hard nanocrystals） and （No. NSF- CMMI-1553986） （nanomanufacturing）.
文摘Ternary FeCoNi metallic nanostructures have attracted significant attention due to their high saturation magnetization, unique mechanical properties, and large corrosion resistance. In this study, we report a controlled synthesis of ternary FeCoNi nanocrystals using solution-based epitaxial core-shell nanotechnology. The thickness and stoichiometry of the FeCoNi nanocrystals affect their magnetic characteristics, which can be controlled by a phase transformation-induced tetragonal distortion. Furthermore, surface oxidation of the stoichiometry-controlled FeCoNi nanostructures can drastically enhance their magnetic coercivity （up to 8,881.60e for AuCu-FeCo）, and optimize the AuCu-FeCo08Ni0.2 performance corresponding to the saturated magnetization of 134.4 emu-g-1 and coercivity of 4,036.70e, which opens the possibility of developing rare-earth free high energy nanomagnets.
