Hydrogen-Substituted Superconductors SmFeAsO(1-x)Hx Misidentified As Oxygen-Deficient SmFeAsO(1-x)
We investigated the preferred electron dopants at the oxygen sites of 1111-type SmFeAsO by changing the atmospheres around the precursor with the composition of Sm:Fe:As:O = 1:1:1:1 - x in high-pressure synthesis. Under H2O and H2 atmospheres, hydrogens derived from H2O or H2 molecules were introduc...
Gespeichert in:
Veröffentlicht in: | Inorganic chemistry 2015-12, Vol.54 (23), p.11567-11573 |
---|---|
Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | We investigated the preferred electron dopants at the oxygen sites of 1111-type SmFeAsO by changing the atmospheres around the precursor with the composition of Sm:Fe:As:O = 1:1:1:1 - x in high-pressure synthesis. Under H2O and H2 atmospheres, hydrogens derived from H2O or H2 molecules were introduced into the oxygen sites as a hydride ion, and SmFeAsO(1-x)Hx was obtained. However, when the H2O and H2 sources were removed from the synthetic process, nearly stoichiometric SmFeAsO was obtained and the maximum amount of oxygen vacancies introduced remained x = 0.05(4). Density functional theory calculations indicated that substitution of hydrogen in the form of H(-) is more stable than the formation of an oxygen vacancy at the oxygen site of SmFeAsO. These results strongly imply that oxygen-deficient SmFeAsO(1-x) reported previously is SmFeAsO(1-x)Hx with hydride ion incorporated unintentionally during high-pressure synthesis. |
---|---|
ISSN: | 1520-510X |
DOI: | 10.1021/acs.inorgchem.5b02248 |