Modulated systems in external fields : conditions for the presence of reentrant phase diagrams
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/158511 |
Resumo: | We introduce a coarse-grained model capable of describing the phase behavior of two-dimensional ferromagnetic systems with competing exchange and dipolar interactions, as well as an external magnetic field. An improved expression for the mean-field entropic contribution allows us to compute the phase diagram in the whole temperature versus external field plane. We find that the topology of the phase diagram may be qualitatively different depending on the ratio between the strength of the competing interactions. In the regime relevant for ultrathin ferromagnetic films with perpendicular anisotropy we confirm the presence of inverse-symmetry breaking from a modulated phase to a homogeneous one as the temperature is lowered at constant magnetic field, as reported in experiments. For other values of the competing interactions we show that reentrance may be absent. Comparing thermodynamic quantities in both cases, as well as the evolution of magnetization profiles in the modulated phases, we conclude that the reentrant behavior is a consequence of the suppression of domain wall degrees of freedom at low temperatures at constant fields. |
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Mendoza Coto, AlejandroBilloni, Orlando VitoCannas, Sergio A.Stariolo, Daniel Adrian2017-05-25T02:27:30Z20160163-1829http://hdl.handle.net/10183/158511001009917We introduce a coarse-grained model capable of describing the phase behavior of two-dimensional ferromagnetic systems with competing exchange and dipolar interactions, as well as an external magnetic field. An improved expression for the mean-field entropic contribution allows us to compute the phase diagram in the whole temperature versus external field plane. We find that the topology of the phase diagram may be qualitatively different depending on the ratio between the strength of the competing interactions. In the regime relevant for ultrathin ferromagnetic films with perpendicular anisotropy we confirm the presence of inverse-symmetry breaking from a modulated phase to a homogeneous one as the temperature is lowered at constant magnetic field, as reported in experiments. For other values of the competing interactions we show that reentrance may be absent. Comparing thermodynamic quantities in both cases, as well as the evolution of magnetization profiles in the modulated phases, we conclude that the reentrant behavior is a consequence of the suppression of domain wall degrees of freedom at low temperatures at constant fields.application/pdfengPhysical review. New York. Vol. 94, no. 5 (Aug. 2016), 054404,8 p.Diagramas de faseFilmes finos magneticosTransições magnéticasQuebra de simetriaAnisotropia magnética perpendicularCampos magnéticosModulated systems in external fields : conditions for the presence of reentrant phase diagramsEstrangeiroinfo: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:UFRGSORIGINAL001009917.pdf001009917.pdfTexto completo (inglês)application/pdf1846080http://www.lume.ufrgs.br/bitstream/10183/158511/1/001009917.pdf389b82855b64b19103b1e30fd6f7a3eaMD51TEXT001009917.pdf.txt001009917.pdf.txtExtracted Texttext/plain36089http://www.lume.ufrgs.br/bitstream/10183/158511/2/001009917.pdf.txt7a3a12c9797c1b8f28f6e8a963452273MD5210183/1585112017-08-17 02:36:04.985529oai:www.lume.ufrgs.br:10183/158511Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2017-08-17T05:36:04Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
title |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
spellingShingle |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams Mendoza Coto, Alejandro Diagramas de fase Filmes finos magneticos Transições magnéticas Quebra de simetria Anisotropia magnética perpendicular Campos magnéticos |
title_short |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
title_full |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
title_fullStr |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
title_full_unstemmed |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
title_sort |
Modulated systems in external fields : conditions for the presence of reentrant phase diagrams |
author |
Mendoza Coto, Alejandro |
author_facet |
Mendoza Coto, Alejandro Billoni, Orlando Vito Cannas, Sergio A. Stariolo, Daniel Adrian |
author_role |
author |
author2 |
Billoni, Orlando Vito Cannas, Sergio A. Stariolo, Daniel Adrian |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Mendoza Coto, Alejandro Billoni, Orlando Vito Cannas, Sergio A. Stariolo, Daniel Adrian |
dc.subject.por.fl_str_mv |
Diagramas de fase Filmes finos magneticos Transições magnéticas Quebra de simetria Anisotropia magnética perpendicular Campos magnéticos |
topic |
Diagramas de fase Filmes finos magneticos Transições magnéticas Quebra de simetria Anisotropia magnética perpendicular Campos magnéticos |
description |
We introduce a coarse-grained model capable of describing the phase behavior of two-dimensional ferromagnetic systems with competing exchange and dipolar interactions, as well as an external magnetic field. An improved expression for the mean-field entropic contribution allows us to compute the phase diagram in the whole temperature versus external field plane. We find that the topology of the phase diagram may be qualitatively different depending on the ratio between the strength of the competing interactions. In the regime relevant for ultrathin ferromagnetic films with perpendicular anisotropy we confirm the presence of inverse-symmetry breaking from a modulated phase to a homogeneous one as the temperature is lowered at constant magnetic field, as reported in experiments. For other values of the competing interactions we show that reentrance may be absent. Comparing thermodynamic quantities in both cases, as well as the evolution of magnetization profiles in the modulated phases, we conclude that the reentrant behavior is a consequence of the suppression of domain wall degrees of freedom at low temperatures at constant fields. |
publishDate |
2016 |
dc.date.issued.fl_str_mv |
2016 |
dc.date.accessioned.fl_str_mv |
2017-05-25T02:27:30Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/158511 |
dc.identifier.issn.pt_BR.fl_str_mv |
0163-1829 |
dc.identifier.nrb.pt_BR.fl_str_mv |
001009917 |
identifier_str_mv |
0163-1829 001009917 |
url |
http://hdl.handle.net/10183/158511 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Physical review. New York. Vol. 94, no. 5 (Aug. 2016), 054404,8 p. |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
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application/pdf |
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Repositório Institucional da UFRGS |
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Repositório Institucional da UFRGS |
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