Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry
We report measurements on MgB2 up to ∼40 GPa. Increasing pressure yields a monotonous decrease of the lattice parameters and of the c/a ratio, but no structural transition down to parameters smaller than those of AlB2. The transition superconducting temperature also decreases with temperature in a s...
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2001
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01631829_v64_n17_p1725021_Bordet http://hdl.handle.net/20.500.12110/paper_01631829_v64_n17_p1725021_Bordet |
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paper:paper_01631829_v64_n17_p1725021_Bordet2023-06-08T15:13:55Z Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry magnesium derivative article chemical structure conductance conductor measurement pressure stoichiometry structure analysis temperature dependence We report measurements on MgB2 up to ∼40 GPa. Increasing pressure yields a monotonous decrease of the lattice parameters and of the c/a ratio, but no structural transition down to parameters smaller than those of AlB2. The transition superconducting temperature also decreases with temperature in a sample-dependent way. The results are explained by an increase of the filling of the two-dimensional pxy bands with pressure, the Mg stoichiometry determining the starting position of the Fermi level. Our measurements indicate that these hole bands are the relevant ones for superconductivity. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01631829_v64_n17_p1725021_Bordet http://hdl.handle.net/20.500.12110/paper_01631829_v64_n17_p1725021_Bordet |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
magnesium derivative article chemical structure conductance conductor measurement pressure stoichiometry structure analysis temperature dependence |
| spellingShingle |
magnesium derivative article chemical structure conductance conductor measurement pressure stoichiometry structure analysis temperature dependence Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry |
| topic_facet |
magnesium derivative article chemical structure conductance conductor measurement pressure stoichiometry structure analysis temperature dependence |
| description |
We report measurements on MgB2 up to ∼40 GPa. Increasing pressure yields a monotonous decrease of the lattice parameters and of the c/a ratio, but no structural transition down to parameters smaller than those of AlB2. The transition superconducting temperature also decreases with temperature in a sample-dependent way. The results are explained by an increase of the filling of the two-dimensional pxy bands with pressure, the Mg stoichiometry determining the starting position of the Fermi level. Our measurements indicate that these hole bands are the relevant ones for superconductivity. |
| title |
Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry |
| title_short |
Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry |
| title_full |
Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry |
| title_fullStr |
Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry |
| title_full_unstemmed |
Absence of a structural transition up to 40 GPa in MgB2 and the relevance of magnesium nonstoichiometry |
| title_sort |
absence of a structural transition up to 40 gpa in mgb2 and the relevance of magnesium nonstoichiometry |
| publishDate |
2001 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01631829_v64_n17_p1725021_Bordet http://hdl.handle.net/20.500.12110/paper_01631829_v64_n17_p1725021_Bordet |
| _version_ |
1768543509613117440 |