简介:TherepresentativesampleLa0.58Dy0.09Ca0.33MnO3ofDydopedLa0.67Ca0.33MnO3rare-earthmanganiteswasinvestigated.ThemostimportanteffectofDydopingistointroducethemagnetoimpurityandformthespinclusterswhichinducedramaticallylargeCMRinLa0.58Dy0.09Ca0.33MnO3.Thefittingresultsoffield-inducedresistivitydecreasetotheBrillouinfunctionindicatethattheCMRiscausedbythespindependenthoppingbetweenspinclusters.Itisthemagneticfieldthatreducesthesizeofspinclustersandinducesafield-inducedirreversibleCMRbehaviour.