Magnetic interactions and magnetocaloric effect in (La0.5Pr0.5)0.6Ba0.4MnO3: Effect of A-site co-doping

TL;DR

This study investigates the structural, magnetic, and magnetocaloric properties of a co-doped manganite, revealing a second-order phase transition and quantifying its magnetic entropy change, with analysis of doping effects on these properties.

Contribution

It provides new insights into how A-site co-doping influences the magnetic and magnetocaloric behavior of (La,Pr)0.6Ba0.4MnO3, including critical exponents and phase transition characteristics.

Findings

Second-order PM-FM transition at ~277 K

Maximum magnetic entropy change of ~3.22 J/kg·K under 5 T

Critical exponents close to mean field and 3D-Ising models

Abstract

We report on the structural, magnetic, and magnetocaloric properties of polycrystalline (La0.5Pr0.5)0.6Ba0.4MnO3 (LPBMO), which was fabricated by a conventional solid-state reaction method. LPBMO undergoes a second-order paramagnetic to ferromagnetic (PM-FM) phase transition around a Curie temperature TC ~ 277 K. The maximum magnetic entropy change is ~ 3.22 J kg-1 K-1 for a magnetic field change of 5 T. Based on the modified-Arrott plot and the iterative Kouvel Fisher methods, a set of critical exponents (beta = 0.514, gamma = 1.164, and delta = 3.265) are determined. These values are close to those expected for the mean field model with long range interactions below TC and for the 3D-Ising model with short range interactions above TC. Effect of A-site co-doping (La,Pr) on the magnetic and magnetocaloric properties of LPBMO is analyzed and discussed.