The magnetocaloric effect of Sr vacancies in La0.7Sr0.3−x□xMnO3 compounds with x = 0 and 0.05 was studied. From the magnetic measurements as a function of temperature and magnetic applied field, a large magnetic entropy change (ΔSM) at Curie temperature was deduced. Thus, ΔSM was found to reduce for La0.7Sr0.25□0.05MnO3 samples (−1.78J/kgK for x = 0 and 1.60J/kgK for x = 0.05 under a magnetic field change of μ0ΔH = 2T). This reduction was accompanied by a decrease in the Curie temperature (TC = 374 and 366K for x = 0 and 0.05, respectively).

Magnetocaloric Effect on Strontium Vacancies in Polycrystalline La0.7Sr0.3−x□xMnO3. M.Bejar, N.Sdiri, M.Hussein, S.Mazen, E.Dhahri: Journal of Magnetism and Magnetic Materials, 2007, 316[2], e566-8