Suppression of charge-ordering and appearance of magnetoresistance in a spin-cluster glass manganite La0.3Ca0.7Mn0.8Cr0.2O3

摘要: Abstract The magnetic properties of electron-doped manganite La 0.3 Ca 0.7 MnO 3 and Mn 0.8 Cr 0.2 O polycrystalline samples prepared by sol–gel technique have been investigated between 5 300 K in fields ranging from 0 to 5 T. transition at 260 K, attributed charge ordering , is completely suppressed the Cr-substituted sample while onset a remanence followed appearance irreversibility lower temperatures observed both samples. These features indicate that ferromagnetic clusters coexist with either an antiferromagnetic phase for or spin-cluster glass lowest temperatures. exponential temperature dependence resistivity consistent small polaron hopping model 120 K T known show no magnetoresistance, large negative magnetoresistance below 120 K. CMR spin dependent and/or domains.