Reversibility in the adiabatic temperature-change of Pr0.73Pb0.27MnO3
Özet
The investigation of structure, magnetic and magnetocaloric properties of Pr0.73Pb0.27MnO3 perovskite has been studied by using the X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and magnetization. The X-ray diffraction pattern shows reflections typical of the perovskite structure with cubic symmetry. The field cooled (FC), zero-field-cooled(ZFC) and field-heated(FH) thermomagnetic measurements at 50 Oe indicate a sharp change of magnetization at the phase-transition (T-C approximate to 234 K). The magnetic entropy changes were determined from M(H) isotherms that were measured at various temperatures around T-C. The magnetic entropy changes in magnetic field changes of 1T and 2T were 2.4 Jkg(-1) K-1 and 3.8 Jkg(-1) K-1, respectively. The adiabatic temperature change of this material, Delta T-ad, was measured by means of an adiabatic calorimeter directly. The results indicate a maximum adiabatic temperature change produced by a magnetic field change of 3 T is 2.5 Kat 236 K. (C) 2013 Elsevier B.V. All rights reserved.
