Influence of La3+ site substitution on the structural, magnetic and magnetocaloric properties of ZnFe2-xLaxO4 (x=0.00, 0.001, 0.005 and 0.01) spinel zinc ferrites

Abstract ZnFe 2 O 4 ferrite nanoparticles are arousing a great interest in the biomedical field, in particular for magnetic hyperthermia application, thanks to their beneficial physical and chemical properties. Here, we report the discovery of a magnetocaloric effect at low temperature in ZnFe 2− x La x O 4 ferrite nanoparticles (≤10 K). Indeed, sol–gel technique was employed to synthesize ZnFe 2−x La x O 4 (x = 0.00, 0.001, 0.005 and 0.01) spinel. Structural, magnetic and magnetocaloric properties of ZnFe 2 − x La x O 4 spinel were investigated in detail. The XRD results show that the crystallite size was reduced with the increase in La 3+ cations. Magnetic properties and magnetocaloric response of ZnFe 2 − x La x O 4 ferrite have been studied as a function of La 3+ concentration. It was demonstrated that, Neel temperature (T N ) decreased slightly with the La 3+ content. Furthermore, the magnetic moment decreased with the addition of La 3+ cations. The peak of magnetic entropy change ( - Δ S M max ) slowly decreased. Interestingly, a notable increase in the value of the relative cooling power (RCP) was observed with La 3+ doping.