Unusual superconducting state at 49 K in electron-doped CaFe2As2 at ambient pressure.
Proc Natl Acad Sci U S A
; 108(38): 15705-9, 2011 Sep 20.
Article
en En
| MEDLINE
| ID: mdl-21911404
ABSTRACT
We report the detection of unusual superconductivity up to 49 K in single crystalline CaFe(2)As(2) via electron-doping by partial replacement of Ca by rare-earth. The superconducting transition observed suggests the possible existence of two phases one starting at 49 K, which has a low critical field < 4 Oe, and the other at 21 K, with a much higher critical field > 5 T. Our observations are in strong contrast to previous reports of doping or pressurizing layered compounds AeFe(2)As(2) (or Ae122), where Ae = Ca, Sr, or Ba. In Ae122, hole-doping has been previously observed to generate superconductivity with a transition temperature (T(c)) only up to 38 K and pressurization has been reported to produce superconductivity with a T(c) up to 30 K. The unusual 49 K phase detected will be discussed.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Arsenicales
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Compuestos Ferrosos
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Compuestos de Calcio
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Temperatura de Transición
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Conductividad Eléctrica
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Electrones
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos