Specific heat measurements near Tc in some magnetic systems

Abstract

This paper reports the development of an AC calorimetric technique for the measurement of relative specific heat of metallic samples suitable for high pressure studies up to 30 kbar in the temperature range 25-1000 degree C. The PC based electronic instrumentation developed in our laboratory employs a novel circuit to maintain a constant power pulse through the sample, so that the variation of the sample resistance due to either temperature or pressure is taken care of. The performance of this technique is demonstrated through measurements on an archetypal itinerant ferromagnet like Nickel at ambient pressure. New data on the behaviour of specific heat near Tc in an amorphous ferromagnet Co65 Fe5 Mo2 Si16 B12 up to 15 kbar are presented.