Quasicrystals (QCs) have a peculiar structural order characterized by quasiperiodicity and non-crystallographical point group symmetry. To reveal their characteristic physical property reflecting the peculiar structural order, specific heat measurements were performed for Al–Pd–Mn icosahedral QCs (i-QCs) and a series of crystal approximants (CAs) of 2/1- 1/1- and 1/0-cubic types at 400–1200 K. The measured specific heat per atom at constant pressure was converted to that at constant volume by using data of the thermal expansion coefficient and bulk modulus. Below ∼700 K, the values of all the specimens of i-QCs and CAs were close to ( Boltzman’s constant), i.e., they obeyed Dulong–Petit’s law. With further increase in temperature, the i-QCs showed a dramatic increase in with increasing temperature, and reached at 1100 K. In contrast, the 2/1 CAs showed a similar but slightly smaller increase in whereas the 1/1 and 1/0 CAs showed a negligible increase. The systematic behavior of in the order of CAs and QC demonstrates that a large excessive specific heat is a characteristic feature of QCs, reflecting the peculiarity of their structural order. Its possible physical mechanism was discussed in terms of anharmonic atomic vibrations, electronic excitations, and phasonic excitations.

准晶体 (QC) 具有特殊的结构顺序，其特征是准周期性和非晶体点群对称性。为了揭示它们反映特殊结构顺序的特征物理性质，对 Al-Pd-Mn 二十面体 QC (i-QC) 和一系列 2/1-1/1- 和 1 的晶体近似物 (CA) 进行了比热测量/0-cubic 类型在 400–1200 K。通过使用热膨胀系数和体积模量的数据，将在恒定压力下测量的每个原子的比热转换为恒定体积下的比热。在~700 K以下，i-QCs和CAs的所有样本的值都接近于（玻尔兹曼常数），即，他们遵守 Dulong-Petit 定律。随着温度的进一步升高，i-QCs 显示出随着温度升高而急剧增加，并达到1100 K。相比之下，2/1 CA 显示出类似但略小的增加，而 1/1 和 1/0 CA 显示出可以忽略不计的增加。CA 和 QC 顺序的系统行为表明，大的超额比热是 QC 的一个特征，反映了其结构顺序的特殊性。从非谐原子振动、电子激发和声子激发的角度讨论了其可能的物理机制。