Abstract

The temperature dependences of the veloсity of hypersound (V(T)) in solutions with various concentrations of guanidine hydrochloride (GndHCl) are studied by Brillouin–Mandelstam light scattering spectroscopy in the temperature range from 263 to 353 K. It is shown that the temperature dependence of the sound velocity has a pronounced maximum at low concentrations of GndHCl. An increase in the concentration of GndHCl in a solution is accompanied by a shift of the maximum to the low-temperature region and an increase in the absolute values of the sound velocity, which means a decrease in the adiabatic compressibility over the entire range of studied temperatures. The temperature dependence of the adiabatic compressibility is constructed at low concentrations of GndHCl. The contribution of relaxation processes to the temperature behavior of the attenuation of hypersound in solutions of GndHCl is determined. It is shown that their behavior is activated thermally and described by the Arrhenius law. The values of the activation energy of relaxation processes are calculated. Possible mechanisms that underlie the observed phenomena are discussed.

中文翻译：

---

千兆赫兹频率范围内各种浓度的盐酸胍溶液的弹性特性

摘要

超音速（V（T））在263至353 K的温度范围内，通过布里渊-曼德尔斯坦光散射光谱法研究了具有各种浓度的盐酸胍（GndHCl）的溶液。研究表明，在低浓度下，声速对温度的依赖性最大的GndHCl。溶液中GndHCl浓度的增加伴随着最大值向低温区域的移动以及声速绝对值的增加，这意味着在整个研究范围内绝热压缩率降低温度。绝热可压缩性的温度依赖性是在低浓度的GndHCl下构建的。确定了弛豫过程对GndHCl溶液中超音衰减的温度行为的贡献。结果表明，它们的行为被热激活，并由阿伦尼乌斯定律描述。计算弛豫过程的活化能值。讨论了观察到的现象的可能机制。