We report superconductivity, which is achieved in Sr1-xNaxFe2As2 at Tc = 36.5 K for x = 0.47. Single crystals of Na-substituted SrFe2As2 up to 2 2 mm2 were grown from NaF flux. The superconducting transition temperature with a narrow width less than 2 K, confirmed by both magnetic and resistivity measurements, indicates the high quality of our samples. The upper critical fields (0) = 87 T and (0) = 217.5 T are extremely high. The anisotropy ratio $\gamma$ ~ 2.5 is close to that of other hole-or electron-doped 122 phases but lower than $\gamma$ ~ 4.3 – 5 of phases from the 1111 series and much lower than $\gamma$ ~ 7 – 10 of superconducting cuprates. Magnetic relaxation measurements, which are consistent with the collective pinning model, reveal that the flux-creep rate in Na substituted 122 SrFe2As2 is smaller than in 1111 type iron pnictides.
%0 Conference Paper
%1 shlyk2014
%A Shlyk, Larysa
%A Bischoff, Markus
%A Rose, Eva
%A Niewa, Rainer
%B 6th Forum on New Materials - Part C
%D 2014
%I Trans Tech Publications
%K crystals superconductivity
%P 150-155
%R 10.4028/www.scientific.net/AST.95.150
%T Superconductivity at Tc = 36.5 K in Na-Substituted SrFe2As2 Single Crystals
%V 95
%X We report superconductivity, which is achieved in Sr1-xNaxFe2As2 at Tc = 36.5 K for x = 0.47. Single crystals of Na-substituted SrFe2As2 up to 2 2 mm2 were grown from NaF flux. The superconducting transition temperature with a narrow width less than 2 K, confirmed by both magnetic and resistivity measurements, indicates the high quality of our samples. The upper critical fields (0) = 87 T and (0) = 217.5 T are extremely high. The anisotropy ratio $\gamma$ ~ 2.5 is close to that of other hole-or electron-doped 122 phases but lower than $\gamma$ ~ 4.3 – 5 of phases from the 1111 series and much lower than $\gamma$ ~ 7 – 10 of superconducting cuprates. Magnetic relaxation measurements, which are consistent with the collective pinning model, reveal that the flux-creep rate in Na substituted 122 SrFe2As2 is smaller than in 1111 type iron pnictides.
@inproceedings{shlyk2014,
abstract = {We report superconductivity, which is achieved in Sr1-xNaxFe2As2 at Tc = 36.5 K for x = 0.47. Single crystals of Na-substituted SrFe2As2 up to 2 {\texttimes } 2 mm2 were grown from NaF flux. The superconducting transition temperature with a narrow width less than 2 K, confirmed by both magnetic and resistivity measurements, indicates the high quality of our samples. The upper critical fields (0) = 87 T and (0) = 217.5 T are extremely high. The anisotropy ratio $\gamma$ ~ 2.5 is close to that of other hole-or electron-doped 122 phases but lower than $\gamma$ ~ 4.3 – 5 of phases from the 1111 series and much lower than $\gamma$ ~ 7 – 10 of superconducting cuprates. Magnetic relaxation measurements, which are consistent with the collective pinning model, reveal that the flux-creep rate in Na substituted 122 SrFe2As2 is smaller than in 1111 type iron pnictides.},
added-at = {2018-03-09T15:03:41.000+0100},
author = {Shlyk, Larysa and Bischoff, Markus and Rose, Eva and Niewa, Rainer},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2b7ce9c72613f9a15db99b5da593798c7/ulrikeoffenbeck},
booktitle = {6th Forum on New Materials - Part C},
doi = {10.4028/www.scientific.net/AST.95.150},
interhash = {b4cf59df742af26e7f89c0b7cbdfc991},
intrahash = {b7ce9c72613f9a15db99b5da593798c7},
keywords = {crystals superconductivity},
month = {12},
pages = {150-155},
publisher = {Trans Tech Publications},
series = {Advances in Science and Technology},
timestamp = {2018-03-09T14:03:41.000+0100},
title = {Superconductivity at Tc = 36.5 K in Na-Substituted SrFe2As2 Single Crystals},
volume = 95,
year = 2014
}
