Study of magnetic and electrical properties of PrCaBaMnO manganite.

The magnetic properties and magnetocaloric effect (MCE) in PrCaBaMnO have been investigated supplemented by electrical data. X-ray diffraction shows that the sample crystallizes in the distorted orthorhombic system with the space group. PrCaBaMnO undergoes paramagnetic-ferromagnetic (PM-FM) phase transition at ∼ 85 K. For a magnetic field change of 5 T, the maximum value of the magnetic entropy change (-Δ ) is estimated to be 4.4 J kg K around with a large relative cooling power (RCP) value of 263.5 J kg. While the modified Arrott plots suggested that the magnetic transition belongs to the second order phase transitions, the universal curves of the rescaled magnetic entropy (Δ ) proved the opposite. The electrical properties of PrCaBaMnO have been investigated using impedance spectroscopy techniques. The dc-resistivity ( ) study shows the presence of semiconductor behavior. Ac-conductivity ( ) analysis shows that the conductivity is governed by a hopping process. From the analysis of the alternating regime, the exponent variation obtained is in good agreement with Mott theory. The impedance spectrum analysis reveals the presence of a relaxation phenomenon. Based on these analyzes, the sample can be modeled by an electrical equivalent circuit.