Nanoscopic Characteristics of Anhydrite (100) Growth

The growth of anhydrite (100) surface in contact with supersaturated aqueous solutions (βanh = 1 -3.6) under low hydrothermal conditions (T = 60 -120 ºC) has been studied by use of a hydrothermal atomic force microscope (HAFM). Our observations show that growth on this surface occurs by lateral spre...

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Detalles Bibliográficos
Autores: Morales, Juan, Astilleros García-Monge, José Manuel, Fernández Díaz, María Lourdes
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/42943
Acceso en línea:https://hdl.handle.net/20.500.14352/42943
Access Level:acceso abierto
Palabra clave:549.761.31
Anhydrite
Cristalografía (Geología)
Mineralogía (Geología)
2506.11 Mineralogía
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oai_identifier_str oai:docta.ucm.es:20.500.14352/42943
network_acronym_str ES
network_name_str España
repository_id_str
spelling Nanoscopic Characteristics of Anhydrite (100) GrowthMorales, JuanAstilleros García-Monge, José ManuelFernández Díaz, María Lourdes549.761.31AnhydriteCristalografía (Geología)Mineralogía (Geología)2506.11 MineralogíaThe growth of anhydrite (100) surface in contact with supersaturated aqueous solutions (βanh = 1 -3.6) under low hydrothermal conditions (T = 60 -120 ºC) has been studied by use of a hydrothermal atomic force microscope (HAFM). Our observations show that growth on this surface occurs by lateral spreading ofmonomolecular layers (3.5 Å in height) and is highly anisotropic, with [001] and [001] alternating as fast and slow directions in successive monolayers. This anisotropic growth is evidence of strong structural control, which becomes less intense as temperature and/or supersaturation increases. The growth anisotropy affects the development of spirals, determining the combination of fast-moving and slow-moving steps to form bilayer steps around the emergence point of screw dislocations and leading to nonconstant spread rates. As a result, the overall efficiency of spiral growth mechanism is highly dependent on the interaction between slow-moving bilayers and fast-moving monolayers originating from different dislocations. Formation of two-dimensional nuclei occurs only at Tg>º80 ºCand βanhg>2, two-dimensional nucleation density always being very low (< 1nucleus/μm2) under the conditions explored. These facts, together with the slow kinetics of anhydrite growth in comparison to the much faster kinetics of gypsum growth, might explain the frequentmetastable formation of gypsum crystals under temperatures corresponding to the stability field of anhydrite.American Chemical SocietyUniversidad Complutense de Madrid20122012-01-0120122012-01-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/42943reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Atribución-NoComercial-SinDerivadas 3.0 Españahttps://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/429432026-06-02T12:44:21Z
dc.title.none.fl_str_mv Nanoscopic Characteristics of Anhydrite (100) Growth
title Nanoscopic Characteristics of Anhydrite (100) Growth
spellingShingle Nanoscopic Characteristics of Anhydrite (100) Growth
Morales, Juan
549.761.31
Anhydrite
Cristalografía (Geología)
Mineralogía (Geología)
2506.11 Mineralogía
title_short Nanoscopic Characteristics of Anhydrite (100) Growth
title_full Nanoscopic Characteristics of Anhydrite (100) Growth
title_fullStr Nanoscopic Characteristics of Anhydrite (100) Growth
title_full_unstemmed Nanoscopic Characteristics of Anhydrite (100) Growth
title_sort Nanoscopic Characteristics of Anhydrite (100) Growth
dc.creator.none.fl_str_mv Morales, Juan
Astilleros García-Monge, José Manuel
Fernández Díaz, María Lourdes
author Morales, Juan
author_facet Morales, Juan
Astilleros García-Monge, José Manuel
Fernández Díaz, María Lourdes
author_role author
author2 Astilleros García-Monge, José Manuel
Fernández Díaz, María Lourdes
author2_role author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 549.761.31
Anhydrite
Cristalografía (Geología)
Mineralogía (Geología)
2506.11 Mineralogía
topic 549.761.31
Anhydrite
Cristalografía (Geología)
Mineralogía (Geología)
2506.11 Mineralogía
description The growth of anhydrite (100) surface in contact with supersaturated aqueous solutions (βanh = 1 -3.6) under low hydrothermal conditions (T = 60 -120 ºC) has been studied by use of a hydrothermal atomic force microscope (HAFM). Our observations show that growth on this surface occurs by lateral spreading ofmonomolecular layers (3.5 Å in height) and is highly anisotropic, with [001] and [001] alternating as fast and slow directions in successive monolayers. This anisotropic growth is evidence of strong structural control, which becomes less intense as temperature and/or supersaturation increases. The growth anisotropy affects the development of spirals, determining the combination of fast-moving and slow-moving steps to form bilayer steps around the emergence point of screw dislocations and leading to nonconstant spread rates. As a result, the overall efficiency of spiral growth mechanism is highly dependent on the interaction between slow-moving bilayers and fast-moving monolayers originating from different dislocations. Formation of two-dimensional nuclei occurs only at Tg>º80 ºCand βanhg>2, two-dimensional nucleation density always being very low (< 1nucleus/μm2) under the conditions explored. These facts, together with the slow kinetics of anhydrite growth in comparison to the much faster kinetics of gypsum growth, might explain the frequentmetastable formation of gypsum crystals under temperatures corresponding to the stability field of anhydrite.
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-01-01
2012
2012-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/42943
url https://hdl.handle.net/20.500.14352/42943
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Atribución-NoComercial-SinDerivadas 3.0 España
https://creativecommons.org/licenses/by-nc-nd/3.0/es/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
Atribución-NoComercial-SinDerivadas 3.0 España
https://creativecommons.org/licenses/by-nc-nd/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15.300724

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