The magneto-caloric properties of La0.7Ca0.11Sr0.19MnO3 nanoparticles prepared by a one-step, nonaqueous synthesis

We report herein on a new route to synthesize La0.7Ca0.11Sr0.19MnO3 perovskite crystalline nanoparticles by using microwave radiation under argon atmosphere in a nonaqueous solvent of benzyl alcohol. It was found that the product shows a large magneto-caloric effect at room temperature. The structure, magnetic properties, and magneto-caloric effect have been investigated. X-ray diffraction and electron diffraction revealed that the products are of a pure single-phase rhombohedral structure. Transmission electron microscopy measurements showed that the particle sizes are in the range of 15–35 nm when the as-prepared material precursor was annealed to 700 °C for 4 h, and 30–40 nm when the calcinated temperature is increased to 900 °C. The Curie temperature of the compound was determined by thermo-magnetic measurements and the magneto-caloric effect was studied in terms of isothermal magnetic entropy change (ΔSm). These results suggest that the material may be a suitable candidate as a working substance in magnetic refrigeration near room temperature. -- Highlights: ► La0.7Ca0.11Sr0.19MnO3 nanocrystals were synthesized by a simple one-step MW radiation process. ► The MW synthesis is completed in 5 min. ► La0.7Ca0.11Sr0.19MnO3 nanoparticles were prepared by using benzyl alcohol as a solvent. ► La0.7Ca0.11Sr0.19MnO3 nanoparticles show a large magneto-caloric effect at room temperature