Measurement of low-temperature specific heat

TLDR

Low‑temperature specific‑heat measurements (0.1–60 K) have recently benefited from advances in design and instrumentation, especially for small‑sample calorimetry. This review surveys large‑ and small‑sample calorimetry techniques below 60 K, providing references for deeper investigation. The authors examine reliable LTSH data for 84 elements, discuss measurement challenges, and detail recent progress in radioactive‑sample, high‑field, and sub‑100 µg calorimetry, concluding with emerging microcalorimetry for nanogram samples.

Abstract

The measurement of low-temperature specific heat (LTSH) (0.1 K<T<60 K) has seen a number of breakthroughs both in design concepts and instrumentation in the last 15 years—particularly in small sample calorimetry. This review attempts to provide an overview of both large and small sample calorimetry techniques at temperatures below 60 K, with sufficient references to enable more detailed study. A comprehensive review is made of the most reliable measurements of the LTSH of 84 of the elements to illustrate briefly some of the problems of measurements and analysis, as well as to provide additional references. More detail is devoted to three special areas of low-temperature calorimetry that have seen rapid development recently—(1) measurement of the specific heat of highly radioactive samples, (2) measurement of the specific heat of materials in high magnetic fields (18 T), and (3) measurement of the specific heat of very small (100 μg) samples. The review ends with a brief discussion of the frontier research currently underway on microcalorimetry for nanogram sample weights.