The expected low field magnetocaloric effect of La0.7Ba0.3MnO3 manganite at room temperature

• La0.7Ba0.3MnO3 manganite was prepared by the sol–gel method.
• Magnetic measurements at 50 Oe, 100 Oe and 200 Oe show the FM–PM transition at Tc=302 KTc=302 K.
• The low field MCE of La0.7Ba0.3MnO3 manganite has been studied using phenomenological.
• The room temperature ΔS  , RCP and ΔCpΔCp increases with the magnetic fields.
• The universal curve reveals the second order transition of La0.7Ba0.3MnO3 compound.

La0.7Ba0.3MnO3 manganite oxide was prepared by the sol–gel method. X-ray diffraction has shown the high homogeneity of the compound and Reitveld refinement has proved the R-3C rhombohedral structure. The temperature dependence of magnetization at different applied magnetic fields of 50 Oe, 100 Oe and 200 Oe shows a magnetic phase transition at room temperature around 302 K. The magnetocaloric properties and the related parameters have been calculated theoretically based on a phenomenological model. The results include the magnetic field dependence of magnetic entropy change, relative cooling power and specific heat. The constructed universal curve of the magnetic entropy change has proved the second order nature of magnetic phase transition in the studied compound.