LOW - TEMPERATURE AC MICROCALORIMETER AND POTENTIALITIES OF THE AC TECHNIQUE

The potentialities of ac calorimetry are investigated experimentally and theoretically. The effects of the sample-holder and of the heat-leakage into the wires on the measured temperature-oscillations are discussed. It is shown that the effects can lead to incorrect measurements. A proper choice of materials and external parameters enables the construction of the calorimeter with sensitivity of about 10(-8) J/K at 5K. The presented calorimeter gives an opportunity to measure the heat-capacity temperature dependencies in the steady-state mode with a resolution of about 0.01K in the range 1-300K.