Magnetocaloric effect of gadolinium in high magnetic fields

The magnetocaloric effect of gadolinium has been measured directly in pulsed magnetic fields up to 620.16em0exT. The maximum observed adiabatic temperature change is ΔTad=60.50.16em0exK, the initial temperature T₀ being just above 3000.16em0exK. The field dependence of ΔTad is found to follow the usual H2/3 law, with a small correction in H4/3. However, as H is increased, a radical change is observed in the dependence of ΔTad on T₀, at H=const. The familiar caret-shaped peak situated at T₀=TC becomes distinctly asymmetric, its high-temperature slope becoming more gentle and evolving into a broad plateau. For yet higher magnetic fields, μ₀H1400.16em0exT, calculations predict a complete disappearance of the maximum near TC and an emergence of a new very broad maximum far above TC.