| Autor: |
Lv B; Texas Center for Superconductivity, University of Houston, Houston TX 77204-5002, USA., Deng L, Gooch M, Wei F, Sun Y, Meen JK, Xue YY, Lorenz B, Chu CW |
| Jazyk: |
angličtina |
| Zdroj: |
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2011 Sep 20; Vol. 108 (38), pp. 15705-9. Date of Electronic Publication: 2011 Sep 12. |
| DOI: |
10.1073/pnas.1112150108 |
| Abstrakt: |
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. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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