Magnetocaloric effect of gadolinium in high magnetic fields

The magnetocaloric effect of gadolinium has been measured directly in pulsed magnetic fields up to 62 T. The maximum observed adiabatic temperature change is ΔT_ad = 60.5 K, the initial temperature T₀ being just above 300 K. The field dependence of ΔTad is found to follow the usual H^2/3 law, with a small correction in H^4/3. However, as H is increased, a radical change is observed in the dependence of ΔT_ad on T₀, at H = const. The familiar caret-shaped peak situated at T₀ = T_C becomes distinctly asymmetric, its high-temperature slope becoming more gentle and evolving into a broad plateau. For yet higher magnetic fields, μ₀H ≥ 140 T, calculations predict a complete disappearance of the maximum near T_C and an emergence of a new very broad maximum far above T_C.