Flenner Elijah, Szamel Grzegorz
Chemistry Department, Colorado State University, Fort Collins, CO 80523, USA.
Sci Adv. 2025 Apr 11;11(15):eadu6097. doi: 10.1126/sciadv.adu6097.
Comprehending sound damping is integral to understanding the anomalous low temperature properties of glasses. After decades of studies, Rayleigh scaling of the sound attenuation coefficient with frequency, [Formula: see text], became generally accepted. Rayleigh scaling invokes a picture of scattering from defects. It is unclear how to define glass defects. Here, we use a particle level contribution to sound damping to determine areas in the glass that contribute more to sound damping than other areas, which allows us to define defects. Over a range of stability, sound damping scales linearly with the fraction of particles in the defects. However, sound is still attenuated in ultrastable glasses where no defects are identified. We show that sound damping in these glasses is due to nearly uniformly distributed non-affine forces that arise after macroscopic deformation. To fully understand sound attenuation in glasses, one has to consider contributions from defects and a defect-free background, which represents a different paradigm of sound damping in glasses.
理解声阻尼是理解玻璃异常低温特性不可或缺的一部分。经过数十年的研究，声衰减系数随频率的瑞利标度关系，即[公式：见原文]，已被普遍接受。瑞利标度关系引发了一幅由缺陷引起散射的图景。目前尚不清楚如何定义玻璃缺陷。在此，我们利用粒子水平对声阻尼的贡献来确定玻璃中对声阻尼贡献比其他区域更大的区域，这使我们能够定义缺陷。在一定的稳定性范围内，声阻尼与缺陷中粒子的比例呈线性标度关系。然而，在未识别出缺陷的超稳定玻璃中，声音仍然会衰减。我们表明，这些玻璃中的声阻尼是由于宏观变形后出现的几乎均匀分布的非仿射力所致。要全面理解玻璃中的声衰减，必须考虑缺陷和无缺陷背景的贡献，这代表了玻璃中声阻尼的一种不同范式。
