Structural characterization and magnetic field dependence of the magnetocaloric properties in Pr0.8Na0.05K0.15MnO3 ceramic

Pr0.8Na0.05K0.15MnO3 sample was prepared by solid-state reaction method. Refinement of the X-ray diffraction patterns shows that the sample is single phase and crystallizes in the orthorhombic structure with Pbnm space group. This result was confirmed by using the electron diffraction pattern for the sample using the [0 0 1] orientation. Analyzing temperature and field dependences of magnetization around the ferromagnetic-paramagnetic transition reveals the sample undergoing the second-order magnetic phase transition. The isothermal entropy changes ΔS as a function of temperature in different magnetic fields were determined. A phenomenological model is used to calculate magnetic and magnetocaloric properties of Pr0.8Na0.05K0.15MnO3 compound. The maximum values of ΔSmax and the relative cooling power (RCP) increase with increasing applied magnetic field. Landau theory and phenomenological universal curves of entropy change confirm the second order phase transition.