Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities

Fixed vacancies (non-magnetic impurities) are placed along the centre of Ising strips in order to study the wetting behaviour in this confined system, by means of numerical simulations analysed with the aid of finite size scaling and thermodynamic integration methods. By considering strips of size L...

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Autores principales: Trobo, Marta Liliana, Albano, Ezequiel Vicente
Formato: Articulo
Lenguaje:Inglés
Publicado: 2016
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/102542
https://ri.conicet.gov.ar/11336/48101
http://iopscience.iop.org/article/10.1088/0953-8984/28/12/125001/meta
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id I19-R120-10915-102542
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Física
Tricritical wetting
Confined matterials
Interfaces
spellingShingle Física
Tricritical wetting
Confined matterials
Interfaces
Trobo, Marta Liliana
Albano, Ezequiel Vicente
Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities
topic_facet Física
Tricritical wetting
Confined matterials
Interfaces
description Fixed vacancies (non-magnetic impurities) are placed along the centre of Ising strips in order to study the wetting behaviour in this confined system, by means of numerical simulations analysed with the aid of finite size scaling and thermodynamic integration methods. By considering strips of size L x M (L ≪ M) where short-range competitive surface fields (H<sub>s</sub>) act along the M-direction, we observe localization–delocalization transitions of the interface between magnetic domains of different orientation (driven by the corresponding surface fields), which are the precursors of the wetting transitions that occur in the thermodynamic limit. By placing vacancies or equivalently non-magnetic impurities along the centre of the sample, we found that for low vacancy densities the wetting transitions are of second order, while by increasing the concentration of vacancies the transitions become of first order. Second- and first-order lines meet in tricritical wetting points (H tric sw, tric T tric w), where Hsw tric and T w tric are the magnitude of the surface field and the temperature, respectively. In the phase diagram, tricritical points shift from the high temperature and weak surface field regime at large vacancy densities to the T → 0, Hsw tric → 1 limit for low vacancy densities. By comparing the locations of the tricritical points with those corresponding to the case of mobile impurities, we conclude that in order to observe similar effects, in the latter the required density of impurities is much smaller (e.g. by a factor 3–5). Furthermore, a proper density of non magnetic impurities placed along the centre of a strip can effectively pin rather flat magnetic interfaces for suitable values of the competing surface fields and temperature.
format Articulo
Articulo
author Trobo, Marta Liliana
Albano, Ezequiel Vicente
author_facet Trobo, Marta Liliana
Albano, Ezequiel Vicente
author_sort Trobo, Marta Liliana
title Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities
title_short Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities
title_full Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities
title_fullStr Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities
title_full_unstemmed Tricritical wetting in the two-dimensional Ising magnet due to the presence of localized non-magnetic impurities
title_sort tricritical wetting in the two-dimensional ising magnet due to the presence of localized non-magnetic impurities
publishDate 2016
url http://sedici.unlp.edu.ar/handle/10915/102542
https://ri.conicet.gov.ar/11336/48101
http://iopscience.iop.org/article/10.1088/0953-8984/28/12/125001/meta
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AT albanoezequielvicente tricriticalwettinginthetwodimensionalisingmagnetduetothepresenceoflocalizednonmagneticimpurities
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