Observation of superconductivity at 30~46 K in A(x)Fe2Se2(A = Li, Na, Ba, Sr, Ca, Yb, and Eu).
Sci Rep
; 2: 426, 2012.
Article
em En
| MEDLINE
| ID: mdl-22645642
ABSTRACT
New iron selenide superconductors by intercalating smaller-sized alkali metals (Li, Na) and alkaline earths using high-temperature routes have been pursued ever since the discovery of superconductivity at about 30â
K in KFe2Se2, but all have failed so far. Here we demonstrate that a series of superconductors with enhanced T(c) = 30â¼46â
K can be obtained by intercalating metals, Li, Na, Ba, Sr, Ca, Yb, and Eu in between FeSe layers by the ammonothermal method at room temperature. Analysis on their powder X-ray diffraction patterns reveals that all the main phases can be indexed based on body-centered tetragonal lattices with aâ¼3.755-3.831 Å while câ¼15.99-20.54 Å. Resistivities show the corresponding sharp transitions at 45â
K and 39â
K for NaFe2Se2 and Ba0.8Fe2Se2, respectively, confirming their bulk superconductivity. These findings provide a new starting point for studying the properties of these superconductors and an effective synthetic route for the exploration of new superconductors as well.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Selênio
/
Compostos de Ferro
/
Condutividade Elétrica
/
Temperatura Alta
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article