Field-tuned magnetocaloric effect in metamagnetic manganite system

We have investigated the origin of the huge magnetocaloric effect in a manganite system with ferro-antiferromagnetic phase mixture at low temperatures. We carried out magnetic measurements in fields up to 100 kOe in order to show that both a high hysteretic behavior and a metamagnetic transition in the antiferromagnetic state are responsible for the large magnetic entropy change. The temperature where the maximum of the magnetic entropy change occurs can be tuned by varying the maximum value of the applied magnetic field to the system. This last procedure can open a new perspective for charge-ordered manganite applications to magnetic refrigeration at low temperatures. (C) 2004 American Institute of Physics.