Magnetic and magnetocaloric properties of (1 − x)La<inf>0.7</inf>Sr<inf>0.3</inf>MnO<inf>3</inf>/xNaF composites

Abstract

© 2018 Elsevier B.V. (1 − x)La0.7Sr0.3MnO3/xNaF (x = 0.05, 0.15, 0.2) composites were synthesized by the conventional solid-state synthesis route, while the sodium fluoride NaF was added to the stoichiometric amount of La2O3, SrCO3 and Mn2O3, that allowed to reduce the synthesis temperature of composites in respect to the pure lanthanum strontium manganite. The phase purity and microstructures of composites were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Magnetocaloric effect was investigated by means of field dependence magnetization measurements. The significant affect of the additive NaF to the final size and morphology of (1 − x)La0.7Sr0.3MnO3/xNaF composite samples was observed. Though the high-concentration samples (x = 0.15, 0.2) exhibit the lower magnetic entropy changes ΔSM in respect to the pure La0.7Sr0.3MnO3, the expanded temperature dependence of ΔSM curves leads to the slightly higher values of the relative cooling power.