Modeling the magnetic isotherms of (La0.56Ce0.14)Sr0.30MnO3 by a mean-field scaling method and estimation of magnetic entropy change
Abstract
Wereportastudyonthemagneticpropertiesofthe(La0.56Ce0.14)Sr0.30MnO3 perovskite,byamean-field
method. Byscalingoftheexperimentalmagnetizationdata,themean-fieldexchangeparameter λ andthe BS
functionoftheequationofstate ⎡⎣
⎤⎦
BS H He /T xch ( + ) aredirectlydetermined,aswellastheorderofthephase
transition.Thespinquantumnumberofthemanganitehasbeenalsodetermined.Themean-fieldscalinghas
beenusedtoestimatemagneticentropychange (−ΔSM) within thethermodynamics ofthemodelandwithout
usingtheusualnumericalintegrationofaMaxwellrelation.Themaximaofthepositiveabsolutevalueof
(−ΔSM) upon variationoftheappliedmagnetic fieldat1and5Tareabout1.68and5.04Jkg1 K1, re-
spectively.Satisfactoryagreementbetweenthemean-fieldmodelandexperimentalbehaviorhasbeenfound.
Keywords
Perovskites, Mean-field scaling, Exchange parameter, Spin, Magnetic entropy