Grain size modification in the magnetocaloric and non-magnetocaloric transitions in La0.5Ca0.5MnO3 probed by direct and indirect methods

The influence of the grain size in the magnetic properties of phase separated manganites is an important issue evidenced more than a decade ago. The formation of long range ordered phases is suppressed as the grain size decreases giving place to a metastable state instead of the ground state. In this work we present a study of the magnetocaloric effect in the prototypical manganite La0.5Ca0.5MnO3 as function of the grain size. The differences obtained using direct and indirect methods are discussed in the framework of domain walls in the ferromagnetic phase of the system.