A new range of specific perovskite-type materials with structural, magnetic and magnetocaloric properties: La0.67Ca0.33-xSrxMn0.98Fe0.02O3 (0.15 ≤ x ≤ 0.3)

The effect of strontium doping on the structural, magnetic and magnetocaloric properties of La(0.67)Ca(0.33-x)Sr(x)Wn(0.98)Fe(0.02)O(3) samples for (x = 0.15; 0.2.and 0.3) has been investigated. Analysis using X-ray diffraction shows there is an orthorhombic structure with Pnma space group symmetry for x = 0.15 compound, whereas there is a rhombohedral structure exhibiting R (3) over barc space group symmetry found for x = 0.2, and x = 0.3 compounds. A second-order magnetic phase transition from ferromagnetic to paramagnetic state transition is evidenced for all samples, with Curie temperature (T-C) values equal to 329 K, 330 K and 350 K and that respectively for x = 0.15, 0.2 and 0.3. Based on isothermal magnetization measurements versus applied magnetic field at several temperatures around T-C, the magnetic entropy change was calculated, which is very close to that approximated by the Landau theory for.x = 0.15. Under an applied magnetic field of 5 T, one can see the maximum magnetic entropy change (-Delta S-M(max)) values, which are around 4.89, 4.71 and 3.35 J.kg(-1).K-1 for x = 0.15, 0.2, and 0.3 respectively. It confirms that close to room temperature, these manganites are admirably potential functional materials, which can be applied as solid state magnetic refrigerants.

Automated summary

The influence of strontium doping on the structural, magnetic, and magnetocaloric properties of La-based complex oxides has been investigated. Different crystal structures were observed for samples with varying doping concentrations. The magnetic entropy change measurements showed that strontium doping significantly affects the magnetic properties of the material, making it a potential candidate for magnetic refrigeration applications.