RIA: Structural Relaxations in Glass-Forming Oxide Melts

玻璃形成过程中结构松弛的本质将利用液体氧化物系统的粘性行为利用布里渊光散射技术进行研究。GHz频率范围内的信号与复数模数有关，允许在原子尺度上直接研究粘弹性松弛。在布里渊光谱中反射的过程包括较大分子单元的合作振动，涉及键断裂和重新定向的结构重排，以及扩散粒子之间的动量交换。探头和被研究物质之间不需要机械耦合，这消除了高温测量的一些困难，便于研究玻璃化转变区的粘弹性现象。通过互补的数值模拟，阐明了实验观测与玻璃形成液体的结构特征之间的基本关系。

The nature of structural relaxations during the glass formation process will be investigated using the viscous behavior of liquid oxide systems using the Brillouin light scattering technique. A signal in the GHz frequency range, related to a complex modulus, allows direct study of viscoelastic relaxation on an atomistic scale. Processes which reflect in the Brillouin spectrum include cooperative vibrations of larger molecular units, structural rearrangements involving bond breaking and reorientations and momentum exchange between diffusing particles. No mechanical coupling is necessary between the probe and the investigated substance, which eliminates some of the difficulties of high temperature measurements and facilitates the study of viscoelastic phenomena in the glass transition region. The fundamental relation between the experimental observations and the structural characteristics of glass.forming liquids is elucidated by complementary numerical simulations.