Measurement of heat capacity of superionic silver sulfide (argentite β-Ag₂S) revealed that nanocrystalline argentite has a higher heat capacity than coarse-crystalline argentite. It is shown that the heat capacity of nanocrystalline substances includes an additional positive contribution caused by the limitation of the phonon spectrum on the part of low and high frequencies due to a small particle size. The estimation of this contribution on the basis of experimental differences in the heat capacities of nano- and coarse-crystalline argentite β-Ag₂S in the region of its existence, 470–850 K, made it possible to determine for the first time the velocities of propagation of longitudinal and transverse elastic vibrations c_l and c_t and elastic stiffness constants c₁₁, c₁₂ and c₄₄. It is established that with a rise in temperature the elastic characteristics of argentite decrease. The anisotropy of elastic properties of cubic argentite was analyzed, and the crystal lattice directions corresponding to the largest and the least values of elastic moduli were determined. An increase of the temperature from 470 to 850 K leads to a small decrease of the elastic anisotropy of cubic β-Ag₂S argentite.

中文翻译：

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超离子立方硫化银β-Ag2S的弹性

的超离子硫化银的热容量（辉银矿β-测量的Ag ₂ S）表明，纳米晶辉银矿具有比粗晶辉银矿更高的热容量。结果表明，纳米晶体物质的热容量还包括一个额外的正贡献，这是由于小粒径导致低频和高频声子频谱受到限制而引起的。在纳米和粗晶辉银矿β-Ag的热容量实验差异的基础上这种贡献的估计₂ S IN它的存在，470-850 K的区域，使得有可能确定用于第一次纵向和横向弹性振动的传播速度c _l和c_t和弹性刚度常数c ₁₁， c ₁₂和c ₄₄。已经确定，随着温度的升高，银辉石的弹性特性降低。分析了立方银辉石的弹性各向异性，并确定了与弹性模量的最大值和最小值相对应的晶格方向。从470至850ķ引线的温度的立方β-Ag的弹性各向异性的少量减少增加₂小号辉银矿。