Diversity of microstructural phenomena in superconducting and non-superconducting Rb(x)Fe(2-y)Se2: a transmission electron microscopy study at the atomic scale.
Inorg Chem
; 52(24): 14419-27, 2013 Dec 16.
Article
em En
| MEDLINE
| ID: mdl-24283501
ABSTRACT
Superconducting (SC) and non-superconducting (non-SC)Rb(x)Fe(2-y)Se2 crystals were grown using the "self-flux" technique in order to assign the microstructural changes to the onset of superconductivity in complex iron selenides. The crystals were thoroughly characterized by magnetic susceptibility and transport measurements as well as powder X-ray diffraction. Special attention was paid to the comparison of the microstructure of the crystals with and without the superconducting transition by means of transmission electron microscopy (TEM). It is shown that the alternation of ordered and disordered regions on the sample surface and along the c-axis is characteristic for both SC and non-SC materials and therefore does not necessarily represent a trigger of superconductivity. Three types of electron diffraction patterns were found for the superconducting Rb(x)Fe(2-y)Se2 sample, of which one is observed for the first time and originates from alkali metal ordering. Moreover, for the superconducting Rb(x)Fe(2-y)Se2 material a monoclinic distortion with ß â¼ 87° was observed, leading to the space group I2/m. This monoclinic distortion seems to be an attribute of the superconducting material only, whereas in the non-superconducting sample the orthogonality of the crystallographic axes is preserved.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Inorg Chem
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Federação Russa
País de publicação:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA