Determination of the magnetocaloric entropy change in the presence of phase separation and metastability: The case of Eu0.58Sr0.42MnO3

• The entropy change was investigated in an oxide with pronounced metastable effects.
• A strong scatter is observed among results derived from several indirect methods.
• It is found that even the calorimetric approach can be proned to artefacts.
• A method is proposed to evaluate a “real” magnetocaloric entropy change.

The magnetocaloric effect (MCE) in the manganite Eu0.58Sr0.42MnO3 was derived by different methods, in a field range very sensitive to the phenomenon of phase separation. It turns out that a strong scatter in the MCE features was observed. When the applied field is less than the field required to complete the transition, it is found that the MCE can be strongly overestimated by “standard” indirect measurements. A way to properly estimate the MCE around a first order transition in the presence of phase separation and metastability is proposed.