Stacking nanoscale-building blocks into onedimensional(1D)assemblies with collective physical properties is a frontier in designing materials.However,the formation of 1D arrays using weak magnetic fields and an in-dep...Stacking nanoscale-building blocks into onedimensional(1D)assemblies with collective physical properties is a frontier in designing materials.However,the formation of 1D arrays using weak magnetic fields and an in-depth understanding of their magnetic properties remain challenging.Here,low-dimensional assemblies of iron oxide nanocubes with a disordered arrangement are fabricated at the diethylene-glycol/air interface in the presence of assembly fields(0/1/3/5/30/50 mT).Ring-shaped assemblies gradually transform as the assembly field increases from 0 to 50 mT,first to a porous network consisting of elongated assemblies and then to an aligned array of filaments,in which the aligned filaments are formed when the assembly field is≥3 mT and duration t>14 min.Spin-glass characteristics and static(dynamic)anisotropy factors~2(3)are achieved by tuning the strength of the assembly field.In the presence of a relatively weak assembly field,the interplay between dipolar interactions and disorder with respect to magnetic easy axis alignment leads to spin-glass characteristics.The alignment of the magnetic easy axes and the strength of the dipolar interactions increase with increasing assembly field,resulting in the disappearance of spin-glass characteristics and enhancement of the magnetic anisotropy.This study presents a strategy for obtaining magnetic assemblies with spin-glass behavior and controllable anisotropy while shedding light on the magnetic interactions of low-dimensional assemblies.展开更多
基金financially supported by Shenzhen Science and Technology Project(CYJ20180507182246321 and JCYJ20200109105825504)Swedish Research Council VR(2016-06959)financial support from the Doctoral Joint-Training Program of China Scholarship Council.
文摘Stacking nanoscale-building blocks into onedimensional(1D)assemblies with collective physical properties is a frontier in designing materials.However,the formation of 1D arrays using weak magnetic fields and an in-depth understanding of their magnetic properties remain challenging.Here,low-dimensional assemblies of iron oxide nanocubes with a disordered arrangement are fabricated at the diethylene-glycol/air interface in the presence of assembly fields(0/1/3/5/30/50 mT).Ring-shaped assemblies gradually transform as the assembly field increases from 0 to 50 mT,first to a porous network consisting of elongated assemblies and then to an aligned array of filaments,in which the aligned filaments are formed when the assembly field is≥3 mT and duration t>14 min.Spin-glass characteristics and static(dynamic)anisotropy factors~2(3)are achieved by tuning the strength of the assembly field.In the presence of a relatively weak assembly field,the interplay between dipolar interactions and disorder with respect to magnetic easy axis alignment leads to spin-glass characteristics.The alignment of the magnetic easy axes and the strength of the dipolar interactions increase with increasing assembly field,resulting in the disappearance of spin-glass characteristics and enhancement of the magnetic anisotropy.This study presents a strategy for obtaining magnetic assemblies with spin-glass behavior and controllable anisotropy while shedding light on the magnetic interactions of low-dimensional assemblies.
