Fully automated calorimeter for small samples with improved sensitivity

Abstract

A fully automated microcalorimeter based on the non-adiabatic relaxation method is described. A new multipurpose interface is presented and experimental details are given covering the electronic circuitry for fast and accurate thermometry, data processing, sample preparation and cryogenic environment. Absolute accuracy of the calorimeter is verified by determining the specific heat capacity of copper. The result is compared with the literature. The almost continuous measurement of the heat capacity in the range 1.5K to 30K with high accuracy (within about 1%) makes this microcalorimeter well suited to investigate the heat capacity of small samples in the range of 0.01 mu J/K to 800 mu J/K. This improved sensitivity permits heat capacity measurements of samples weighing less than 50 mg.