Effect of magnetic phase fluctuation on magnetic and magnetocaloric properties of polycrystalline (Nd0.5Sm0.5)0.5(Sr0.75Ba0.25)0.5 MnO3 compound

The magnetic, magnetocaloric and exchange bias properties have been studied for the polycrystalline (Nd0.5Sm0.5)0.5(Sr0.75Ba0.25)0.5MnO3 compound. At low temperature, antiferromagnetic counterpart of this phase separated compound transforms into ferromagnetic via a field induced metamagnetic transition. The absence of the exchange bias effect may be ascribed by the random spin freezing and existence of the paramagnetic phase even in the presence of a cooling magnetic field. Depending upon the value of the cooling field, the coercivity changes significantly. This feature may be associated with the magnetic randomness of the sample. Magnetocaloric effect calculated from M–H data (collected from different measurement protocols) indicate the remarkable modification of the ground state configuration due to magnetic field cycling. The protocol dependence MCE was explained by the field and temperature induced magnetic phase fluctuation.