  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.
