Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2
Dioguardi, A. P.
Shockley, A. C.
Nisson, D. M.
Almasan, C. C.
Curro, N. J.
Date of Issue2012
School of Physical and Mathematical Sciences
Resistivity, magnetization, and microscopic 75As nuclear magnetic resonance (NMR) measurements in the antiferromagnetically ordered state of the iron-based superconductor parent material CaFe2As2 exhibit anomalous features that are consistent with the collective freezing of domain walls. Below T*≈10 K, the resistivity exhibits a peak and downturn, the bulk magnetization exhibits a sharp increase, and 75As NMR measurements reveal the presence of slow fluctuations of the hyperfine field. These features in both the charge and spin response are strongly field dependent, are fully suppressed by H*≈15 T, and suggest the presence of filamentary superconductivity nucleated at the antiphase domain walls in this material.
Physical review B
© 2012 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of can Physical Society. The paper can be found at the following official DOI: [http://dx.doi.org/10.1103/PhysRevB.85.024530]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.