Nonlinear effects induced by mechanical stresses in glass-forming systems far from equilibrium

无序材料中的弹塑性转变通常通过热活化（玻璃化转变）或接近许多氧化物或金属系统的断裂点的强机械变形来引入。很少有人知道的合作相互作用的原子/分子和集团的原子在滞弹性和非线性制度的响应函数，由于外部应力。如果人们普遍接受无序系统表现出各种结构弛豫模式（所谓的α，β和快速过程），这些非线性效应的频率依赖性是非常感兴趣的。它将提供局部变形是通过由激励周围的扩展应力场耦合的α-、β-弛豫模式还是通过快速过程及其局部构型变化进行的信息。我们希望使用力学光谱来探测无序材料中非线性效应的普遍性，特别是在金属玻璃中，但也在氧化物系统和晶体材料中的轨道液体中。后者作为一种相当新的无序材料，对微小的应变变化非常敏感，因此备受关注。

The elastic-plastic transition in disordered materials often is introduced via thermal activation (glass transition) or strong mechanical deformation close to the rupture point of many oxide or metallic systems. Little is known about the cooperative interaction of atoms/molecules and groups of atoms in the anelastic and nonlinear regime of the response functions due to external stress. If one generally accepts that disordered systems exhibit various modes of structural relaxations (so-called α, ß and fast processes) the frequency dependence of these nonlinear effects is of great interest. It would provide information whether local deformations proceed via α-, β-relaxation modes coupled by the extended stress field surrounding an excitation, or via fast processes and their local change of configuration. We would like to use mechanical spectroscopy to probe the universality of the nonlinear effects in disordered material, particularly in metallic glasses but also in oxide systems and orbital liquids inside crystalline materials. The latter is of prime interest as a rather new class of disordered material and very sensitive to small strain changes.