HEAT-CAPACITY OF THICK-FILM RESISTOR THERMOMETERS AND PURE RUO2 AT LOW-TEMPERATURES

The heat capacity of commercial thick-film chip resistors has been mea sured in the temperature range 0.1-2K. Three different types of resist ors used as low temperature thermometers were investigated. The heat c apacity of all samples shows a Schottky-type anomaly with the maximum at 0.4 K amounting to l muJ K-1 for the largest unit. We also report t he data on the specific heat of a thermometer component, RuO2, and sho w that it has no anomalous behaviour. The peak in heat capacity of the se resistors puts limitations on using them as thermometers for low te mperature calorimeters.