Isobaric specific heat capacity (C_p) is an important parameter not only in physics but also for most materials. Its accurate measurement is particularly critical for performance evaluation of thermoelectric materials, but the experiments by differential scanning calorimetry (DSC) often lead to large uncertainties in the measurements, especially at elevated temperatures. In this study, we propose a simple method to determine C_p by measuring the sound velocity (υ) based on lattice vibration and expansion theory. The relative standard error of the υ is smaller than 1%, showing good accuracy and repeatability. The calculated C_p at elevated temperature (>300 K) increases slightly with increasing temperature due to the lattice expansion, which is more reasonable than the Dulong–Petit value.

中文翻译：

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一种测定等压比热容的声速法

等压比热容 ( C _p ) 不仅在物理学中而且对于大多数材料都是一个重要参数。其准确测量对于热电材料的性能评估尤为关键，但差示扫描量热法 (DSC) 的实验通常会导致测量中存在较大的不确定性，尤其是在高温下。在本研究中，我们提出了一种基于晶格振动和膨胀理论通过测量声速 ( υ )来确定C _{p的简单方法。}υ的相对标准误差小于1%，具有良好的准确度和重复性。计算出的C _p由于晶格膨胀，在升高的温度（> 300 K）下随着温度的升高而略有增加，这比 Dulong-Petit 值更合理。