The influence of a minority magnetic phase on the field dependence of the magnetocaloric effect

The field dependence of the magnetic entropy change can be used to detect the existence of a minority magnetic phase without experimentally reaching its Curie temperature. In this work, we present results that could suggest a breakdown of the recently proposed universal behaviour of the magnetocaloric effect in materials with a second-order magnetic phase transition in some La-containing samples. The behaviour of the outlier La-containing materials is an evidence of the existence of minority phases, preventing the construction of the universal curve with a single reference temperature. However, the use of two reference temperatures avoids this difficulty and allows applying the universal curve for practical purposes even with the presence of the minority phase.