Composition dependence of magnetocaloric effect in Sm1-xSr xMnO3 (x=0.3-0.5)

Abstract

We investigated magnetic and magnetocaloric properties in Sm1-x Srx MnO3 (x=0.3-0.5). We report a magnetic field-driven first-order metamagnetic transition in the paramagnetic state in x=0.4 and 0.5 and a second-order transition in x=0.3. The highest magnetic entropy (-Δ Sm =1.41 J/mol K for ΔH=5 T at T=125 K) that occurs in x=0.4 is associated with the metamagnetic transition resulting from the field-induced growth and coalescence of ferromagnetic nanoclusters pre-existing in the paramagnetic state. Our results suggest that manganites with intrinsic nanoscale phase separation can be exploited for magnetic refrigeration. © 2008 American Institute of Physics.