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This content will become publicly available on July 25, 2019

Title: Superconducting and magnetic phase diagram of RbEuFe 4 As 4 and CsEuFe 4 As 4 at high pressure

The recently discovered (Rb,Cs)EuFe 4As 4 compounds exhibit an unusual combination of superconductivity ( T c~35K) and ferromagnetism ( T m~15K). We have performed a series of x-ray diffraction, ac magnetic susceptibility, dc magnetization, and electrical resistivity measurements on both RbEuFe 4As 4 and CsEuFe 4As 4 to pressures as high as ~30GPa. We find that the superconductivity onset is suppressed monotonically by pressure while the magnetic transition is enhanced at initial rates of dT m/dP~1.7K/GPa and 1.5K/GPa for RbEuFe 4As 4 and CsEuFe 4As 4, respectively. Near 7 GPa, T c onset and T m become comparable. At higher pressures, signatures of bulk superconductivity gradually disappear. Room-temperature x-ray diffraction measurements suggest the onset of a transition from tetragonal (T) to a half-collapsed-tetragonal (hcT) phase at ~10GPa (RbEuFe 4As 4) and ~12GPa (CsEuFe 4As 4). In conclusion, the ability to tune T c and T m into coincidence with relatively modest pressures highlights (Rb,Cs)EuFe 4As 4 compounds as ideal systems to study the interplay of superconductivity and ferromagnetism.
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [5] ;  [6] ;  [7] ;  [1]
  1. Univ. of Florida, Gainesville, FL (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)
  3. Univ. of Hawaii at Manoa, Honolulu, HI (United States)
  4. Argonne National Lab. (ANL), Argonne, IL (United States)
  5. Zhejiang Univ., Hangzhou (China)
  6. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  7. Univ. of Alabama at Birmingham, Birmingham, AL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; NA0002928; AC52-07NA27344
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 1; Journal ID: ISSN 2469-9950
American Physical Society (APS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA); German Research Foundation (DFG); National Natural Science Foundation of China (NNSFC); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1461595