MAGNETOCALORIC PROPERTIES OF DOPED LANTHANUM MANGANITE FILMS

LaMnO3 films doped with Ca, Ba, or Sr have been fabricated using the m etalorganic decomposition technique. These films exhibit paramagnetic- to-ferromagnetic phase transitions at 250, 300, and 350 K, respectivel y. By measuring the film magnetization as a function of field and temp erature we have determined the entropy change associated with these tr ansitions. The large magnetization of these materials results in a tot al entropy change a factor of five less than that of gadolinium, the p rototypical high-temperature magnetocaloric material. Improvements in him morphology and composition may provide a further increase in the m agnetization and total entropy change in these materials. (C) 1996 Ame rican Institute of Physics.