Giant magnetocaloric effect near the Curie temperature in the Sm0.6Sr0.4MnO3 manganite

A method is proposed for the calculation of the magnetocaloric effect from simultaneous measurements of thermal expansion and magnetostriction made in different regimes (adiabatic and isothermal). The magnitude of the magnetocaloric effect for Sm0.6Sr0.4MnO3 is estimated. It is found that near the Curie temperature T-C it passes through a maximum to reach a giant value DeltaT = 4.6 K for DeltaB = 0.84 T. In addition, in the neighborhood of T-C, we observed colossal magnetoresistance Delta rho/rho = [rho (H) - rho (0)]/rho (0) = 72% in a weak magnetic field of 0.84 T, a giant negative volume magnetostriction omega = -5 x 10(-4) in a field of the same strength, and a large change in the sample volume DeltaV/V approximate to 0.1%. (C) 2001 MAIK Nauka/lnterperiodica.