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Title: Structural and magnetic phase diagram of CrAs and its relationship with pressure-induced superconductivity

In this paper, we use neutron diffraction to study the structure and magnetic phase diagram of the newly discovered pressure-induced superconductor CrAs. Unlike most magnetic unconventional superconductors where the magnetic moment direction barely changes upon doping, here we show that CrAs exhibits a spin reorientation from the ab plane to the ac plane, along with an abrupt drop of the magnetic propagation vector at a critical pressure (Pc ≈ 0.6 GPa). This magnetic phase transition, accompanied by a lattice anomaly, coincides with the emergence of bulk superconductivity. With further increasing pressure, the magnetic order completely disappears near the optimal Tc regime (P ≈ 0.94 GPa). Moreover, the Cr magnetic moments tend to be aligned antiparallel between nearest neighbors with increasing pressure toward the optimal superconductivity regime. Finally, our findings suggest that the noncollinear helimagnetic order is strongly coupled to structural and electronic degrees of freedom, and that the antiferromagnetic correlations between nearest neighbors might be essential for superconductivity.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [2] ;  [2] ;  [4] ;  [5] ;  [6]
  1. Fudan Univ., Shanghai (China). Dept. of Physics. State Key Lab. of Surface Physics
  2. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). NIST Center for Neutron Research
  3. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). NIST Center for Neutron Research; Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division
  5. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics; Purdue Univ., West Lafayette, IN (United States). Dept. of Physics
  6. Fudan Univ., Shanghai (China). Dept. of Physics. State Key Lab. of Surface Physics. Collaborative Innovation Center of Advanced Microstructures
Publication Date:
OSTI Identifier:
1361298
Grant/Contract Number:
AC05-00OR22725; 91421106; 11374059; 2015CB921302; 13PJ1401100
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 6; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Fudan Univ., Shanghai (China); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Natural Science Foundation of China (NNSFC); Ministry of Science and Technology (China); Shanghai Pujiang Scholar Program (China)
Contributing Orgs:
Univ. of Maryland, College Park, MD (United States); Chinese Academy of Sciences (CAS), Beijing (China); Purdue Univ., West Lafayette, IN (United States)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY