铁磁性非晶合金中受磁化调制的局域流变

本文研究了铁磁性非晶合金的磁化和不均匀结构的动态弛豫过程的相互作用.研究发现,铁磁性非晶合金的磁化态可以通过表面磨损来被改变.伴随磁化态的改变,非晶合金在纳米压痕实验下的局域动态力学行为发生变化.结合三参量黏弹性模型和态转变理论分析发现,通过磁化,非晶合金的微观结构可以被明显改变,其类液区的有效体积、黏度和弛豫时间可以增加3倍以上.与上述现象相反,通过在弹性极限下的纳米压痕循环加载试验,非晶合金的类液区在纳米尺度上的局域流变可以擦除其磁化效应.非晶合金的磁化和局域流变过程的相互作用与其中的自旋-轨道耦合有关;其磁化态和类液区的变化并不影响其与理想玻璃态相关的瞬时剪切模量.该研究有助于理解非晶态磁性材料的动态磁-力学性能,对其应用有着重要的意义.

Magnetization-affected localized flows in ferromagnetic metallic glass

In this paper,the interaction between magnetization and dynamic relaxation of heterogeneous structure in a ferromagnetic metallic glass(MG)is investigated.It is found that the magnetic state of the MG can be changed through wearing its surface.Accompanying with the change of magnetic state,the local dynamic mechanical behavior of the MG was detected by nanoindentation varies.Through analyzing with combination of the three-parameter viscoelastic model and state-transition theory,it is discovered that the microstructure of the glass can be apparently changed by magnetization with the effective size,viscosity of the liquid-like cores and the relaxation time increased by more than 3 times.Inversely,with cycling loading below the elastic limit of the MG using nanoindentation,it is revealed that localized flows of nano-liquid in the glass erase the effect of magnetization.The interaction between magnetization and localized flows relates to spin-orbit coupling in the MG;the change of magnetic state and liquid-like regions in the MG does not affect its instantaneous shear modulus associated with its ideal glassy state.The studies help understand the dynamic magneto-mechanical properties of amorphous magnetic materials,and have technological importance for their applications.