Scaling of the entropy change at the magnetoelastic transition in (formula presented)

Abstract

Differential scanning calorimetry under a magnetic field H has been used to measure the entropy change (formula presented) at the magnetoelastic transition in (formula presented) alloys, for (formula presented) We show that (formula presented) scales with the transition temperature, (formula presented) which is tuned by x and H, from 70 to 310 K. Such a scaling demonstrates that (formula presented) is the relevant parameter in determining the giant magnetocaloric effect in these alloys, and proves that the magnetovolume effects due to H are of the same nature as the volume effects caused by substitution. © 2002 The American Physical Society.