THE SPECIFIC-HEAT OF ALUMEL AND CHROMEL ALLOYS NEAR THEIR MAGNETIC TRANSITIONS

We report the results of specific heat measurements at zero magnetic f ield and normal pressure on chromel (90% Ni-10% Cr) and alumel (95%Ni- 2%Mn-2%Al) alloys using high-resolution a.c. calorimetry. We find a la rge anomaly in the specific heat at 225 K (for chromel) and at 463 K ( for alumel), which is associated with the transition of each alloy int o a ferromagnetic ordering when they are cooled below their correspond ing Curie points. The experimental data for both alloys are compared w ith previously reported specific heat data of pure Ni Near T-c, and fo r both alloys a critical behavior quite similar to Ni is found.