简介:Themeasurementoflow-fieldsusceptibilityXasafunctionoftemperatureTforLa2/3Ca1/3MnO3showsasignificantdownturnin1/X(T)abovetheCurietemperatureTc,abehaviourgenerallyobservedinperovskitemanganites.Suchadownturnisarguedtobeduetothesegregationofferromagneticclusterswithlargerspinsintheparamagneticmatrix.Basedonthisconsideration,aphenomenologicalexpressionforX(T)isproposed,inwhichthetotalsusceptibilityisassumedtobeasumoftwosusceptibilitiesarisingfrommagneticentitiesinthePMbackgroundandtheFMclusterswithT-dependenteffectivespins,respectively.TheresultisingoodagreementwiththeexperimentaldataobtainedinLa2/3Ca1/3MnO3.