Absolute accuracy in membrane-based ac nanocalorimetry

TL;DR

This paper provides a detailed analysis of membrane-based ac nanocalorimetry, deriving analytical expressions for system behavior, and discusses optimal conditions for achieving high accuracy and resolution in measurements.

Contribution

It introduces practical analytical models for the frequency dependence of heat capacity and thermal conductance in membrane-based systems, enhancing understanding and accuracy.

Findings

Analytical expressions match measurements and simulations

Optimal frequency conditions improve measurement accuracy

Membrane properties significantly influence calorimetric results

Abstract

To achieve accurate results in nanocalorimetry a detailed analysis and understanding of the behavior of the calorimetric system is required. There are especially two system-related aspects that should be taken in consideration: the properties of the empty cell and the effect of the thermal link between sample and cell. Here we study these two aspects for a membrane-based system where heater and thermometer are both in good contact with each other and the center of the membrane. Practical, analytical expressions for describing the frequency dependence of heat capacity, thermal conductance, and temperature oscillation of the system are formulated and compared with measurements and numerical simulations. We finally discuss the experimental conditions for an optimal working frequency, where high resolution and good absolute accuracy are combined.