Effect of Eu Doping on Magnetocaloric Effect in Sm_0.6Sr_0.4MnO₃

Abstract

The electrical, magnetic and magnetocaloric properties of Sm_0.6−xEu_xSr_0.4MnO₃ were investigated for x = 0, 0.2 and 0.4. The Curie temperature decreases from 114 K to 62 K and Metal-Insulator transition temperature also decreases with increasing Eu content. A low temperature maximum is found within the long range ferromagnetic order in field-cooled magnetization of x = 0 which shifts down in temperature with increasing Eu doping and goes below the measured temperature range for x = 0.4. The value of maximum magnetic entropy change increases with increasing x (∼ 8 J/kg.K for ΔH = 5 T) with a calculated net Refrigerant Capacity in the range of 270 J/kg. Thus, Eu doping proves to be an efficient method to tune the Curie temperature of the material in order to obtain a significant refrigerant capacity at desired temperatures.

Keywords:

• Manganites
• magnetoresistance
• magnetocaloric

Acknowledgement

Authors acknowledge the National Research Foundation, Singapore (Grant no. NRF-CRP-G-2007-12).