TY - JOUR
T1 - Doping dependence of phase-separation morphology in (Sr,K)Fe 2As2
AU - Wei, F. Y.
AU - Lv, B.
AU - Chen, F.
AU - Sasmal, K.
AU - Shulman, J.
AU - Xue, Y. Y.
AU - Chu, C. W.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/3/14
Y1 - 2011/3/14
N2 - The effects of the possible phase separation on macroscopic transport properties are explored in (Sr,K)Fe2As2. Three probes, the low-field shielding 4πχZFC, the reversible diamagnetization MSC at 5 T, and the specific heat Cp, with different characteristic length scales on the order of 103, 10, and 100 nm, respectively, were used to examine several (Sr1-xKx)Fe 2As2 samples. The data from different probes should be consistent if the sample can be regarded as mesoscopically homogeneous. While this seems to be the case for the optimally doped x=0.45 samples, the apparent transition temperature and the effective superfluid density strongly depend on the probes used for both the underdoped (x=0.3) and the overdoped (x=0.7) samples. Discrepancies of up to a factor of 10 are observed. The data further suggest that both the x=0.3 and x=0.7 samples are better described as Josephson-junction arrays formed over separated superconductive domains of 10-102 nm sizes. Such a morphology evolution may drastically affect the interpretation of the observed doping effects.
AB - The effects of the possible phase separation on macroscopic transport properties are explored in (Sr,K)Fe2As2. Three probes, the low-field shielding 4πχZFC, the reversible diamagnetization MSC at 5 T, and the specific heat Cp, with different characteristic length scales on the order of 103, 10, and 100 nm, respectively, were used to examine several (Sr1-xKx)Fe 2As2 samples. The data from different probes should be consistent if the sample can be regarded as mesoscopically homogeneous. While this seems to be the case for the optimally doped x=0.45 samples, the apparent transition temperature and the effective superfluid density strongly depend on the probes used for both the underdoped (x=0.3) and the overdoped (x=0.7) samples. Discrepancies of up to a factor of 10 are observed. The data further suggest that both the x=0.3 and x=0.7 samples are better described as Josephson-junction arrays formed over separated superconductive domains of 10-102 nm sizes. Such a morphology evolution may drastically affect the interpretation of the observed doping effects.
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U2 - 10.1103/PhysRevB.83.094517
DO - 10.1103/PhysRevB.83.094517
M3 - Article
AN - SCOPUS:79961083749
SN - 1098-0121
VL - 83
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 9
M1 - 094517
ER -