Doped AMnO3 Perovskites Suitable for Use in Magnetic Cooling Devices

Abstract

The magnetocaloric properties of samples of Sm0.55Sr0.45MnO3,(Nd0.28Eu0.72)(0.55)Sr0.45MnO3, and (Nd0.46Tb0.54)(0.55)Sr0.45MnO3ceramics have been investigated in fields up to 1.4 T. The adiabatictemperature change was measured by a direct method. It was establishedthat the Curie temperature Tc and maximum specific adiabatic temperaturechange (per Tesla) near Tc in Sm0.55Sr0.45MnO3,(Nd0.28Eu0.72)(0.55)Sr0.45MnO3, (Nd0.46Tb0.54)(0.55)Sr0.45MnO3 were 126,112 and 76 K and 1.43, 1 and 1 K/T, respectively. The contributions tothe magnetocaloric effect in SM0.55Sr0.45MnO3 were determined with thehelp of a thermodynamic model. It was shown that the main contributionat the magnetic phase transition is the contribution related with theexchange energy change.