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Evidence of non-stoichiometry effects in nanometric manganite perovskites: influence on the magnetic ordering temperature

hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorEPHERRE, Romain
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorPEPIN, Cinta
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorPENIN, Nicolas
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorDUGUET, Etienne
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorMORNET, Stéphane
hal.structure.identifierInstitute of Physics
dc.contributor.authorPOLLERT, Emil
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorGOGLIO, Graziella
dc.date.issued2011
dc.identifier.issn0959-9428
dc.description.abstractEnThis work tends to evidence that the significant chemical modifications observed in nanometric manganites are not concentrated at the surface of the particles and play a key role on their magnetic properties, especially for the lowest strontium-doping. La<sub>1−<i>x</i></sub>Sr<sub><i>x</i></sub>MnO<sub>3</sub> solid solution with a 27 nm-average crystallite size was prepared <i>via</i> the Glycine Nitrate Process. The evolutions <i>versus x</i> of the Curie temperature (<i>T</i><sub>C</sub>) and saturation magnetization of the nanometric solid solution were interpreted taking into account the Goldschmidt tolerance factor, crystallite size, amount of vacancies and the mixed valency of manganese ions. Two distinct populations were distinguished: (i) for <i>x</i> lower than 0.25, the increase of <i>T</i><sub>C</sub> with <i>x</i> could be related to the decreasing amount of cationic vacancies that accommodate the substitution at the A-site of the perovskite framework, simultaneously keeping the content of Mn<sup>4+</sup>% constant; (ii) for <i>x</i> higher than 0.25, the increase of <i>x</i> led to a decrease of the structural distortion, hence favouring orbital overlap and inducing a <i>T</i><sub>C</sub> increase. However, when the amount of Mn<sup>4+</sup> exceeded the value of ≈35%, competitive superexchange antiferromagnetic interactions were promoted. As a result, the observed behaviour was a compromise between these two competitive tendencies and led to a quasi-constant <i>T</i><sub>C</sub>. For <i>x</i> higher than 0.4, the antiferromagnetic interactions became more important, which induced a <i>T</i><sub>C</sub> decrease.
dc.language.isoen
dc.publisherRoyal Society of Chemistry
dc.subjectMagnetism
dc.subjectPerovskites
dc.subjectNanoparticles
dc.subjectManganites
dc.title.enEvidence of non-stoichiometry effects in nanometric manganite perovskites: influence on the magnetic ordering temperature
dc.typeArticle de revue
dc.identifier.doi10.1039/C1JM12137E
dc.subject.halChimie/Matériaux
bordeaux.journalJournal of Materials Chemistry
bordeaux.page14990-14998
bordeaux.volume21
bordeaux.issue38
bordeaux.peerReviewedoui
hal.identifierhal-00626942
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00626942v1
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