Masciovecchio C, Baldi G, Caponi S, Comez L, Di Fonzo S, Fioretto D, Fontana A, Gessini A, Santucci S C, Sette F, Viliani G, Vilmercati P, Ruocco G
Sincrotrone Trieste, strada statale 14 km 163.5, 34012 Basovizza, Trieste, Italy.
Phys Rev Lett. 2006 Jul 21;97(3):035501. doi: 10.1103/PhysRevLett.97.035501. Epub 2006 Jul 18.
We report measurements of the sound attenuation coefficient in vitreous silica, for sound waves of wavelength between 50 and 80 nm, performed with the new inelastic UV light scattering technique. These data indicate that in silica glass a crossover between a temperature-dependent (at low frequency) and a temperature-independent (at high frequency) acoustic attenuation mechanism occurs at Q approximately equal to 0.15 nm(-1). The absence of any signature in the static structure factor at this Q value suggests that the observed crossover should be associated with local elastic constant fluctuations.
我们报告了采用新型非弹性紫外光散射技术，对波长在50至80纳米之间的声波在石英玻璃中的声衰减系数所进行的测量。这些数据表明，在石英玻璃中，在约等于0.15纳米⁻¹的波矢Q处，发生了温度依赖型（低频时）和温度非依赖型（高频时）声学衰减机制之间的转变。在该Q值下静态结构因子中没有任何特征表明，所观察到的转变应与局部弹性常数涨落有关。
