Magnetic and magnetocaloric properties of La0.6Ca0.4MnO3 tunable by particle size and dimensionality

Manganites have been attracted considerable attention due to some intriguing magnetic properties, such as magnetoresistance, spin glass behavior and superparamagnetism. In recent years, some studies point to the effect of particle size and dimensionality of these compounds in their magnetic features. Particularly, LaCaMnO material research is well explored concerning the bulk material. To overcome the lack of the information we successfully produced advanced nanostructures of La0.6Ca0.4MnO3 manganites, namely nanotubes and nanoparticles by using a sol–gel modified method, to determine the size particle effect on the magnetism. The manganites crystal structure, magnetic and magnetocaloric properties were studied in a broad temperature range. Transmission electron microscopy revealed nanoparticles with sizes from 45 up to 223 nm, depending on the calcination temperature. It was found that the magnetic and magnetocaloric properties can be optimized by tuning the particle size; for instance, the magnetic transition broadening by decreasing the particle size. We report the relative cooling power (RCP) of these samples; it was found that the best RCP was observed for the 223 nm particle (508 J/Kg). Finally, this work contributes to the research on the magnetic properties and magnetocaloric potentials in nanostructured systems with distinct morphologies.

Figure – Electron tomography and 3D reconstruction of a La0.6Ca0.4MnO3 nanotube. XY (A) and YZ (B) section of the 3D volume. (C) Relative Cooling Power (RCP) as a function of particle size D for several magnetic fields up to 50 kOe.Figure optionsDownload high-quality image (182 K)Download as PowerPoint slide