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dc.contributor.authorPires, Rafael Fernandopt_BR
dc.contributor.authorPureur Neto, Paulopt_BR
dc.contributor.authorBehar, Monipt_BR
dc.contributor.authorPimentel Junior, Jorge Luizpt_BR
dc.contributor.authorSchaf, Jacobpt_BR
dc.contributor.authorKopelevich, Y.pt_BR
dc.date.accessioned2014-06-13T02:07:14Zpt_BR
dc.date.issued2012pt_BR
dc.identifier.issn0021-8979pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/96545pt_BR
dc.description.abstractWe report on magnetization, magnetoresistance, and Shubnikov-de Haas oscillations experiments in Na-implanted samples of highly oriented pyrolitic graphite (HOPG). Different ion fluences were applied so that samples with Na contents of 0.5, 1.0, 1.5, and 2.0 at. % were obtained in the implanted region. Ferromagnetic-like hysteresis was observed in magnetization experiments where the field was applied parallel to the graphene planes. The observed saturation moment increases systematically as a function of the implanted ion concentration up to Na 1 at. %, where it goes through a maximum before decreasing slightly towards Na 2 at. %. The planar magnetoresistance amplitude at fixed field and temperature closely correlates with the saturation magnetization data. This result suggests that the strong planar magnetoresistance in graphite is at least partially related to a spin dependent mechanism. The magnetoresistance experiments also reveal the occurrence of Shubnikov-de Haas oscillations. The characteristic frequencies and the effective masses could be estimated and do not depend on the Na concentration. The reported experiments show that the expressive enhancement observed in ferromagnetic-like response in Na-implanted HOPG is primarily due to point defects produced by the implantation process.en
dc.format.mimetypeapplication/pdf
dc.language.isoengpt_BR
dc.relation.ispartofJournal of applied physics. New York. Vol. 111, no. 9 (July 2012), 093922, 6 p.pt_BR
dc.rightsOpen Accessen
dc.subjectMomentos magnéticospt_BR
dc.subjectHisterese magnéticapt_BR
dc.subjectMassa efetivapt_BR
dc.subjectImplantacao ionicapt_BR
dc.subjectDistribuição de impurezaspt_BR
dc.subjectSódiopt_BR
dc.subjectGrafitept_BR
dc.titleMagnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphitept_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb000866722pt_BR
dc.type.originEstrangeiropt_BR


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