Stabilization of MgAl2O4 spinel surfaces via doping
Surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. Here, we report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (Mg...
Gespeichert in:
Veröffentlicht in: | Surface science 2016-07, Vol.649 (C), p.138-145 |
---|---|
Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
container_end_page | 145 |
---|---|
container_issue | C |
container_start_page | 138 |
container_title | Surface science |
container_volume | 649 |
creator | Hasan, Md.M. Dholabhai, Pratik P. Castro, Ricardo H.R. Uberuaga, Blas P. |
description | Surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. Here, we report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl2O4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y3+, Gd3+, La3+) and one tetravalent dopant (Zr4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.
[Display omitted]
•Dopant segregation is examined at three low index surfaces of spinel with atomistic calculations.•The {100} surface has the lowest energy, consistent with previous work.•Dopant charge has a larger role on segregation than dopant size.•Dopants change the energy of different surfaces by different amounts.•Doping leads to a larger quantity of {111} facets in equilibrium structures. |
doi_str_mv | 10.1016/j.susc.2016.01.028 |
format | Article |
fullrecord | <record><control><sourceid>elsevier_osti_</sourceid><recordid>TN_cdi_osti_scitechconnect_1256292</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><els_id>S0039602816000479</els_id><sourcerecordid>S0039602816000479</sourcerecordid><originalsourceid>FETCH-LOGICAL-c371t-f5f4882a292848646d8b23e68bc48f584e331cc62a7a1a146ec838e9adeea5513</originalsourceid><addsrcrecordid>eNp9kE9LAzEQxYMoWKtfwNPifdf83yx4KUWrUOlBPYdsdlJT1k1JtgX99GapZ-cyw-O9x_BD6JbgimAi73dVOiRb0XxXmFSYqjM0I6puSloLdY5mGLOmlFm_RFcp7XAe3ogZYm-jaX3vf8zow1AEV7xuFz3d8CLt_QB9kQ7RGQupOHpTdCGL22t04Uyf4OZvz9HH0-P78rlcb1Yvy8W6tKwmY-mE40pRQxuquJJcdqqlDKRqLVdOKA6MEWslNbUhhnAJVjEFjekAjBCEzdHdqTek0etk_Qj204ZhADtqQoXMzdlETyYbQ0oRnN5H_2XityZYT2z0Tk9s9MRGY6Izgxx6OIUgv3_0EKd2GCx0Pk7lXfD_xX8BuV1r3w</addsrcrecordid><sourcetype>Open Access Repository</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype></control><display><type>article</type><title>Stabilization of MgAl2O4 spinel surfaces via doping</title><source>Access via ScienceDirect (Elsevier)</source><creator>Hasan, Md.M. ; Dholabhai, Pratik P. ; Castro, Ricardo H.R. ; Uberuaga, Blas P.</creator><creatorcontrib>Hasan, Md.M. ; Dholabhai, Pratik P. ; Castro, Ricardo H.R. ; Uberuaga, Blas P. ; Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)</creatorcontrib><description>Surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. Here, we report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl2O4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y3+, Gd3+, La3+) and one tetravalent dopant (Zr4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.
[Display omitted]
•Dopant segregation is examined at three low index surfaces of spinel with atomistic calculations.•The {100} surface has the lowest energy, consistent with previous work.•Dopant charge has a larger role on segregation than dopant size.•Dopants change the energy of different surfaces by different amounts.•Doping leads to a larger quantity of {111} facets in equilibrium structures.</description><identifier>ISSN: 0039-6028</identifier><identifier>EISSN: 1879-2758</identifier><identifier>DOI: 10.1016/j.susc.2016.01.028</identifier><language>eng</language><publisher>United States: Elsevier B.V</publisher><subject>Atomistic calculations ; Doping ; MATERIALS SCIENCE ; Spinel ; Surfaces</subject><ispartof>Surface science, 2016-07, Vol.649 (C), p.138-145</ispartof><rights>2016 Elsevier B.V.</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c371t-f5f4882a292848646d8b23e68bc48f584e331cc62a7a1a146ec838e9adeea5513</citedby><cites>FETCH-LOGICAL-c371t-f5f4882a292848646d8b23e68bc48f584e331cc62a7a1a146ec838e9adeea5513</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktohtml>$$Uhttps://dx.doi.org/10.1016/j.susc.2016.01.028$$EHTML$$P50$$Gelsevier$$H</linktohtml><link.rule.ids>230,314,780,784,885,3550,27924,27925,45995</link.rule.ids><backlink>$$Uhttps://www.osti.gov/servlets/purl/1256292$$D View this record in Osti.gov$$Hfree_for_read</backlink></links><search><creatorcontrib>Hasan, Md.M.</creatorcontrib><creatorcontrib>Dholabhai, Pratik P.</creatorcontrib><creatorcontrib>Castro, Ricardo H.R.</creatorcontrib><creatorcontrib>Uberuaga, Blas P.</creatorcontrib><creatorcontrib>Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)</creatorcontrib><title>Stabilization of MgAl2O4 spinel surfaces via doping</title><title>Surface science</title><description>Surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. Here, we report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl2O4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y3+, Gd3+, La3+) and one tetravalent dopant (Zr4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.
[Display omitted]
•Dopant segregation is examined at three low index surfaces of spinel with atomistic calculations.•The {100} surface has the lowest energy, consistent with previous work.•Dopant charge has a larger role on segregation than dopant size.•Dopants change the energy of different surfaces by different amounts.•Doping leads to a larger quantity of {111} facets in equilibrium structures.</description><subject>Atomistic calculations</subject><subject>Doping</subject><subject>MATERIALS SCIENCE</subject><subject>Spinel</subject><subject>Surfaces</subject><issn>0039-6028</issn><issn>1879-2758</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2016</creationdate><recordtype>article</recordtype><recordid>eNp9kE9LAzEQxYMoWKtfwNPifdf83yx4KUWrUOlBPYdsdlJT1k1JtgX99GapZ-cyw-O9x_BD6JbgimAi73dVOiRb0XxXmFSYqjM0I6puSloLdY5mGLOmlFm_RFcp7XAe3ogZYm-jaX3vf8zow1AEV7xuFz3d8CLt_QB9kQ7RGQupOHpTdCGL22t04Uyf4OZvz9HH0-P78rlcb1Yvy8W6tKwmY-mE40pRQxuquJJcdqqlDKRqLVdOKA6MEWslNbUhhnAJVjEFjekAjBCEzdHdqTek0etk_Qj204ZhADtqQoXMzdlETyYbQ0oRnN5H_2XityZYT2z0Tk9s9MRGY6Izgxx6OIUgv3_0EKd2GCx0Pk7lXfD_xX8BuV1r3w</recordid><startdate>20160701</startdate><enddate>20160701</enddate><creator>Hasan, Md.M.</creator><creator>Dholabhai, Pratik P.</creator><creator>Castro, Ricardo H.R.</creator><creator>Uberuaga, Blas P.</creator><general>Elsevier B.V</general><general>Elsevier</general><scope>AAYXX</scope><scope>CITATION</scope><scope>OIOZB</scope><scope>OTOTI</scope></search><sort><creationdate>20160701</creationdate><title>Stabilization of MgAl2O4 spinel surfaces via doping</title><author>Hasan, Md.M. ; Dholabhai, Pratik P. ; Castro, Ricardo H.R. ; Uberuaga, Blas P.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c371t-f5f4882a292848646d8b23e68bc48f584e331cc62a7a1a146ec838e9adeea5513</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2016</creationdate><topic>Atomistic calculations</topic><topic>Doping</topic><topic>MATERIALS SCIENCE</topic><topic>Spinel</topic><topic>Surfaces</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Hasan, Md.M.</creatorcontrib><creatorcontrib>Dholabhai, Pratik P.</creatorcontrib><creatorcontrib>Castro, Ricardo H.R.</creatorcontrib><creatorcontrib>Uberuaga, Blas P.</creatorcontrib><creatorcontrib>Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)</creatorcontrib><collection>CrossRef</collection><collection>OSTI.GOV - Hybrid</collection><collection>OSTI.GOV</collection><jtitle>Surface science</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Hasan, Md.M.</au><au>Dholabhai, Pratik P.</au><au>Castro, Ricardo H.R.</au><au>Uberuaga, Blas P.</au><aucorp>Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)</aucorp><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Stabilization of MgAl2O4 spinel surfaces via doping</atitle><jtitle>Surface science</jtitle><date>2016-07-01</date><risdate>2016</risdate><volume>649</volume><issue>C</issue><spage>138</spage><epage>145</epage><pages>138-145</pages><issn>0039-6028</issn><eissn>1879-2758</eissn><abstract>Surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. Here, we report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl2O4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y3+, Gd3+, La3+) and one tetravalent dopant (Zr4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.
[Display omitted]
•Dopant segregation is examined at three low index surfaces of spinel with atomistic calculations.•The {100} surface has the lowest energy, consistent with previous work.•Dopant charge has a larger role on segregation than dopant size.•Dopants change the energy of different surfaces by different amounts.•Doping leads to a larger quantity of {111} facets in equilibrium structures.</abstract><cop>United States</cop><pub>Elsevier B.V</pub><doi>10.1016/j.susc.2016.01.028</doi><tpages>8</tpages><oa>free_for_read</oa></addata></record> |
fulltext | fulltext |
identifier | ISSN: 0039-6028 |
ispartof | Surface science, 2016-07, Vol.649 (C), p.138-145 |
issn | 0039-6028 1879-2758 |
language | eng |
recordid | cdi_osti_scitechconnect_1256292 |
source | Access via ScienceDirect (Elsevier) |
subjects | Atomistic calculations Doping MATERIALS SCIENCE Spinel Surfaces |
title | Stabilization of MgAl2O4 spinel surfaces via doping |
url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-23T01%3A48%3A48IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-elsevier_osti_&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Stabilization%20of%20MgAl2O4%20spinel%20surfaces%20via%20doping&rft.jtitle=Surface%20science&rft.au=Hasan,%20Md.M.&rft.aucorp=Los%20Alamos%20National%20Laboratory%20(LANL),%20Los%20Alamos,%20NM%20(United%20States)&rft.date=2016-07-01&rft.volume=649&rft.issue=C&rft.spage=138&rft.epage=145&rft.pages=138-145&rft.issn=0039-6028&rft.eissn=1879-2758&rft_id=info:doi/10.1016/j.susc.2016.01.028&rft_dat=%3Celsevier_osti_%3ES0039602816000479%3C/elsevier_osti_%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_id=info:pmid/&rft_els_id=S0039602816000479&rfr_iscdi=true |