Magnetocaloric properties in Ln(0.67)Ba(0.33)Mn(1-x)Fe(x)O(3) (Ln = La or Pr) manganites
Résumé
We have investigated the magnetocaloric properties of Ln(0.67)Ba(0.33)Mn(1-x)Fe(x)O(3) (Ln = La or Pr) manganites with x=0 and 0.05. All compounds present a maximum and large magnetocaloric effect near the Curie temperature (T-C). The associated maximum value of the magnetic entropy change, at 5 T applied change in the magnetic field, is 4.37 J.kg(-1).K-1 for Pr0.67Ba0.33MnO3 manganite with a T-C value of 205 K. The corresponding relative cooling power (RCP) reaches 230 J.kg(-1). All the samples present similar RCP values that are relatively high and are promising materials to be used in ecologically friendly magnetic refrigeration technology. Iron doping reduces both T-C and Delta S-M(max) and spreads the temperature working range with an almost constant RCP and can then be used to tune the working conditions of a refrigerator device. (C) 2011 Elsevier B.V. All rights reserved.