RIA: Structural Relaxations in Glass-Forming Oxide Melts

利用布里渊光散射技术，利用液态氧化物系统的粘性行为来研究玻璃形成过程中结构弛豫的性质。在GHz频率范围内的信号，与复模量有关，允许在原子尺度上直接研究粘弹性松弛。在布里渊光谱中反映的过程包括大分子单位的协同振动，涉及键断裂和取向的结构重排以及扩散粒子之间的动量交换。探针与被测物质之间不需要机械耦合，这消除了高温测量的一些困难，便于研究玻璃化过渡区粘弹性现象。实验结果与玻璃结构特性之间的基本关系。形成液体是通过互补的数值模拟来解释的。

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.