Enhanced near room temperature magnetocaloric effect in La0.6Ca0.4MnO3 for magnetic refrigeration application

Abstract

Perovskite manganite La_0.6Ca_0.4MnO₃ (LCMO) nanomaterials were synthesized by a modified Pechini sol–gel process followed by high temperature sintering. Polyethylene glycol of various molecular weights was used to control the particle size and morphology of the materials. XRD and Scherrer analysis were used to confirm the crystal structure and crystallite size of the LCMO nanomaterials. The LCMO nanomaterials showed a paramagnetic to ferromagnetic transition at 277 K. The maximum change in entropy was calculated to be 19.3 J kg⁻¹ K⁻¹ for a field change of 0–3 T and 8.7 J kg⁻¹ K⁻¹ for a field change of 0–1 T, and the relative cooling power was determined to be 627 J kg⁻¹. The La_0.6Ca_0.4MnO₃ reported in this work demonstrated an enhanced magnetocaloric effect compared to the current literature. These results showed the LCMO nanomaterials to be an excellent candidate for magnetic refrigeration applications as they are less costly in comparison to Gd based compounds.