  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.
