Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/96545 |
Resumo: | We 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. |
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Pires, Rafael FernandoPureur Neto, PauloBehar, MoniPimentel Junior, Jorge LuizSchaf, JacobKopelevich, Y.2014-06-13T02:07:14Z20120021-8979http://hdl.handle.net/10183/96545000866722We 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.application/pdfengJournal of applied physics. New York. Vol. 111, no. 9 (July 2012), 093922, 6 p.Momentos magnéticosHisterese magnéticaMassa efetivaImplantacao ionicaDistribuição de impurezasSódioGrafiteMagnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphiteEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSORIGINAL000866722.pdf000866722.pdfTexto completo (inglês)application/pdf774795http://www.lume.ufrgs.br/bitstream/10183/96545/1/000866722.pdfc3f29a4c25ac652067adc6966b137d65MD51TEXT000866722.pdf.txt000866722.pdf.txtExtracted Texttext/plain28932http://www.lume.ufrgs.br/bitstream/10183/96545/2/000866722.pdf.txt0dbc61515ddccd442bfb87fa22423b80MD52THUMBNAIL000866722.pdf.jpg000866722.pdf.jpgGenerated Thumbnailimage/jpeg2042http://www.lume.ufrgs.br/bitstream/10183/96545/3/000866722.pdf.jpg66e0a3b5c550451b003f8f92722f8c52MD5310183/965452018-10-18 08:13:05.533oai:www.lume.ufrgs.br:10183/96545Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2018-10-18T11:13:05Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
title |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
spellingShingle |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite Pires, Rafael Fernando Momentos magnéticos Histerese magnética Massa efetiva Implantacao ionica Distribuição de impurezas Sódio Grafite |
title_short |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
title_full |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
title_fullStr |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
title_full_unstemmed |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
title_sort |
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite |
author |
Pires, Rafael Fernando |
author_facet |
Pires, Rafael Fernando Pureur Neto, Paulo Behar, Moni Pimentel Junior, Jorge Luiz Schaf, Jacob Kopelevich, Y. |
author_role |
author |
author2 |
Pureur Neto, Paulo Behar, Moni Pimentel Junior, Jorge Luiz Schaf, Jacob Kopelevich, Y. |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Pires, Rafael Fernando Pureur Neto, Paulo Behar, Moni Pimentel Junior, Jorge Luiz Schaf, Jacob Kopelevich, Y. |
dc.subject.por.fl_str_mv |
Momentos magnéticos Histerese magnética Massa efetiva Implantacao ionica Distribuição de impurezas Sódio Grafite |
topic |
Momentos magnéticos Histerese magnética Massa efetiva Implantacao ionica Distribuição de impurezas Sódio Grafite |
description |
We 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. |
publishDate |
2012 |
dc.date.issued.fl_str_mv |
2012 |
dc.date.accessioned.fl_str_mv |
2014-06-13T02:07:14Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
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dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Journal of applied physics. New York. Vol. 111, no. 9 (July 2012), 093922, 6 p. |
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openAccess |
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