Surface termination of MgB2 unveiled by a combination of adsorption experiments and theoretical calculations
Result description
Superconductivity in polycrystalline and thin-film MgB2 is strongly affected by the termination of its surface, but a reliable determination of the surface termination is still a challenging task of surface chemistry. Here, the surface properties of superconducting MgB2 were investigated using a combination of inverse gas chromatography and van der Waals corrected density functional theory calculations. The dispersive surface energy was measured as a function of the surface coverage and its value (58 mJ m(-2) to 48 mJ m(-2)) was verified by high-level non-local EXX + RPA calculations, which predicted that the dispersive contribution to the cleavage energy was 56 mJ m(-2). The isosteric adsorption enthalpies of cyclohexane, dioxane, acetone and acetonitrile molecules were measured on an MgB2 sample and compared to the DFT calculated enthalpies for the Mg-terminated MgB2, B-terminated MgB2 and MgO(001) surfaces. The close agreement between theory and experiment for the Mg-terminated surface suggested that the magnesium termination is the dominant surface phase of MgB2. Thus, combining inverse gas chromatography experiments with theoretical calculations may provide information about the surface termination.
Keywords
The result's identifiers
Result code in IS VaVaI
Alternative codes found
RIV/61388980:_____/19:00504473 RIV/61989592:15310/19:73597863
Result on the web
https://pubs.rsc.org/en/content/articlelanding/2019/CP/C9CP00771G#!divAbstract
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Surface termination of MgB2 unveiled by a combination of adsorption experiments and theoretical calculations
Original language description
Superconductivity in polycrystalline and thin-film MgB2 is strongly affected by the termination of its surface, but a reliable determination of the surface termination is still a challenging task of surface chemistry. Here, the surface properties of superconducting MgB2 were investigated using a combination of inverse gas chromatography and van der Waals corrected density functional theory calculations. The dispersive surface energy was measured as a function of the surface coverage and its value (58 mJ m(-2) to 48 mJ m(-2)) was verified by high-level non-local EXX + RPA calculations, which predicted that the dispersive contribution to the cleavage energy was 56 mJ m(-2). The isosteric adsorption enthalpies of cyclohexane, dioxane, acetone and acetonitrile molecules were measured on an MgB2 sample and compared to the DFT calculated enthalpies for the Mg-terminated MgB2, B-terminated MgB2 and MgO(001) surfaces. The close agreement between theory and experiment for the Mg-terminated surface suggested that the magnesium termination is the dominant surface phase of MgB2. Thus, combining inverse gas chromatography experiments with theoretical calculations may provide information about the surface termination.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Chemistry Chemical Physics
ISSN
1463-9076
e-ISSN
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Volume of the periodical
21
Issue of the periodical within the volume
14
Country of publishing house
GB - UNITED KINGDOM
Number of pages
8
Pages from-to
7313-7320
UT code for WoS article
000464580600006
EID of the result in the Scopus database
2-s2.0-85064014395
Basic information
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Physical chemistry
Year of implementation
2019