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RESEARCH PRODUCT
Magnetic properties of colloidal cobalt nanoclusters
R TorchioC MeneghiniS MobilioG CapelliniA GarcıaJ PrietoMl AlonsoFdez GubiedaVincenzo Turco LiveriA LiveriA LongoAngela Monia RuggirelloNeisius Tsubject
HistoryMaterials scienceAnalytical chemistrychemistry.chemical_elementNanoparticleNanotechnologyXANESComputer Science ApplicationsEducationNanoclustersMetalColloidHysteresisCondensed Matter::Materials Sciencechemistrycobalt nanoparticlesvisual_artvisual_art.visual_art_mediumAntiferromagnetismCobaltSettore CHIM/02 - Chimica Fisicadescription
Abstract. Co nanoclusters were synthesized by an inverse-micelle chemical route. The magnetic and microstructural properties of the nanoparticles have been analyzed as a function of the surfactant (AOT and DEHP) and the drying method. Microstructural analysis has been performed by TEM and XANES; magnetic properties have been studied by hysteresis loops and zero-field cooling - field cooling (ZFC-FC) curves. TEM images show 2 to 4 nm sized particles spherical in shape. XANES measurements point out a significant presence of Co3O4 with metallic Co and some Co2+ bound to the surfactant. The presence of antiferromagnetic Co3O4 explains the magnetic transition observed at low T in both ZFC-FC measurements and hysteresis loops. Finally, the presence of magnetic interactions explains the bigger effective cluster size obtained from hysteresis loops fits (6-10 nm) compared to the sizes observed by TEM (2-4 nm).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-01-01 |