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Title: Phase diagram and neutron spin resonance of superconducting NaFe 1 - x Cu x As

In this paper, we use transport and neutron scattering to study the electronic phase diagram and spin excitations of NaFe 1-xCu xAs single crystals. Similar to Co- and Ni-doped NaFeAs, a bulk superconducting phase appears near x≈2% with the suppression of stripe-type magnetic order in NaFeAs. Upon further increasing Cu concentration the system becomes insulating, culminating in an antiferromagnetically ordered insulating phase near x≈50%. Using transport measurements, we demonstrate that the resistivity in NaFe 1-xCu xAs exhibits non-Fermi-liquid behavior near x≈1.8%. Our inelastic neutron scattering experiments reveal a single neutron spin resonance mode exhibiting weak dispersion along c axis in NaFe 0.98Cu 0.02As. The resonance is high in energy relative to the superconducting transition temperature T c but weak in intensity, likely resulting from impurity effects. These results are similar to other iron pnictides superconductors despite that the superconducting phase in NaFe 1-xCu xAs is continuously connected to an antiferromagnetically ordered insulating phase near x≈50% with significant electronic correlations. Finally, therefore, electron correlations is an important ingredient of superconductivity in NaFe 1-xCu xAs and other iron pnictides.
 [1] ;  [2] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [3] ;  [4] ;  [5]
  1. Beijing Normal Univ. (China). Dept. of Physics
  2. Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Quantum Condensed Matter Division
  4. Chinese Academy of Sciences (CAS), Beijing (China). Beijing National Lab. for Condensed Matter Physics. Inst. of Physics; Collaborative Innovation Center of Quantum Matter, Beijing (China)
  5. Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy; Beijing Normal Univ. (China). Dept. of Physics
Publication Date:
Grant/Contract Number:
AC05-00OR22725; SC0012311; C-1839; 2012CB821401; 11374011; 2014KJJCB27
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 95; Journal Issue: 5; Journal ID: ISSN 2469-9950
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice Univ., Houston, TX (United States); Beijing Normal Univ. (China)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Robert A. Welch Foundation (United States); National Basic Research Program of China; National Natural Science Foundation of China (NNSFC); Fundamental Research Funds for the Central Universities (China)
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; superconductivity; crystalline systems; neutron techniques; transport techniques
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1342609