SPECIFIC-HEAT CAPACITY OF UNDERCOOLED MAGNETIC MELTS

The specific heat capacities of (Co, Ni, Fe)-Pd alloys were determined in the crystalline and metastable undercooled liquid state using diff erential heat flow calorimetry. Applying the melt fluxing technique, t he liquid alloys were undercooled by more than 330 K below their respe ctive liquidus temperatures. For Co100-xPdx (x = 20 and 25 at. %) the undercooled liquid approached the temperature regime of the ferromagne tic crystalline phase. The hear capacity of the liquid samples as a fu nction of temperature-shows a cusplike rise in the vicinity of the Cur ie temperature of the solid state. For (Fe, Ni)-Pd alloys, where the C urie temperatures are far below the crystallization temperatures achie ved in undercooling experiments, an almost constant specific heat at t he same levels of undercooling is observed. These results, together wi th recent magnetization measurements, indicate the existence of a magn etic phase transition in the undercooled liquid state of the Co-Pd all oys. (C) 1996 American Institute of Physics.