Antiferromagnetic spin correlations and pseudogaplike behavior in Ca(Fe1-xCox)2As2 studied by 75As nuclear magnetic resonance and anisotropic resistivity [electronic resource].
- Published
- Washington, D.C. : United States. Dept. of Energy, 2015.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy - Physical Description
- Article numbers 184,504 : digital, PDF file
- Additional Creators
- Ames Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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- Summary
- We report 75As nuclear magnetic resonance (NMR) measurements of single-crystalline Ca(Fe1–xCox)2As2 (x=0.023, 0.028, 0.033, and 0.059) annealed at 350°C for 7 days. From the observation of a characteristic shape of 75As NMR spectra in the stripe-type antiferromagnetic (AFM) state, as in the case of x=0 (TN=170 K), clear evidence for the commensurate AFM phase transition with the concomitant structural phase transition is observed in x=0.023 (TN=106 K) and x=0.028 (TN=53 K). Through the temperature dependence of the Knight shifts and the nuclear spin lattice relaxation rates (1/T1), although stripe-type AFM spin fluctuations are realized in the paramagnetic state as in the case of other iron pnictide superconductors, we found a gradual decrease of the AFM spin fluctuations below a crossover temperature T* that was nearly independent of Co-substitution concentration, and it is attributed to a pseudogaplike behavior in the spin excitation spectra of these systems. The T* feature finds correlation with features in the temperature-dependent interplane resistivity, ρc(T), but not with the in-plane resistivity ρa(T). The temperature evolution of anisotropic stripe-type AFM spin fluctuations is tracked in the paramagnetic and pseudogap phases by the 1/T1 data measured under magnetic fields parallel and perpendicular to the c axis. As a result, based on our NMR data, we have added a pseudogaplike phase to the magnetic and electronic phase diagram of Ca(Fe1–xCox)2As2.
- Report Numbers
- E 1.99:is-j--8859
is-j--8859 - Subject(s)
- Note
- Published through SciTech Connect.
11/06/2015.
"is-j--8859"
Physical Review. B, Condensed Matter and Materials Physics 92 18 ISSN 1098-0121; PRBMDO AM
Cui, J.; Roy, B.; Tanatar, M.; Ran, S.; Bud'ko, S.; Prozorov, R.; Canfield, P.; Furukawa, Y. - Funding Information
- AC02-07CH11358
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