We found that the anomalous magnetic entropy change peak obtained from magnetization measurements in some first-order magnetic phase transition materials may result from the usual data analysis procedure, which does not take into account magnetic irreversibility or mixed-phase regime. The deviations produced are comparable to anomalous effects discussed in the literature and may even exceed the theoretical limit. Our results show that this anomalous magnetic entropy change peak should not necessarily be interpreted as a consequence of the particular physics of the studied system. This also explains its absence in specific heat measurements.
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