Enhanced magnetic refrigeration capacity in phase separated manganites

Multiple phase transitions and magnetic phase coexistence lead to a negative magnetocaloric effect in a wide temperature range of similar to 10-250 K in La(0.215)Pr(0.41)Ca(0.375)MnO(3). A large fraction of the magnetocaloric effect originates from the low temperature phase separated state, which is composed of coexisting, magnetic field dependent charge ordered, and ferromagnetic regions. While the maximum isothermal entropy change is modest, the persistence of the field-dependent phase separated state over a similar to 240 K temperature span yields a refrigeration capacity of similar to 3.2 J/cm(3). Materials with magnetic field dependent phase separation can therefore be used to improve regenerative magnetic refrigerators. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3204694]