Crystalline Electric Field as a Probe for Long-Range Antiferromagnetic Order and Superconducting State of CeFeAsO1-xFx

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.101.217002· OSTI ID:944112

Chi, Songxue ^[1]; Adroja, D. T. ^[2]; GUIDI, T. ^[2]; Bewley, Robert I. ^[2]; Li, Shiliang ^[1]; Zhao, Jun ^[3]; Lynn, J. W. ^[4]; Brown, C. M. ^[4]; Qiu, Y. ^[4]; Luo, J. L. ^[5]; Wang, N. L. ^[5]; Dai, Pengcheng ^[3]

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1. University of Tennessee, Knoxville (UTK)
2. ISIS Facility, Rutherford Appleton Laboratory
3. ORNL
4. National Institute of Standards and Technology (NIST)
5. Chinese Academy of Sciences

We use inelastic neutron scattering to study the crystalline electric field (CEF) excitations of Ce{sup 3+} in CeFeAsO{sub 1-x}F{sub x} (x=0, 0.16). For nonsuperconducting CeFeAsO, the Ce CEF levels have three magnetic doublets in the paramagnetic state, but these doublets split into six singlets when the Fe ions order antiferromagnetically. For superconducting CeFeAsO{sub 0.84}F{sub 0.16} (T{sub c} = 41 K), where the static antiferromagnetic order is suppressed, the Ce CEF levels have three magnetic doublets at {h_bar}{sub {omega}} = 0, 18.7, 58.4 meV at all temperatures. Careful measurements of the intrinsic linewidth {Lambda} and the peak position of the 18.7 meV mode reveal a clear anomaly at T{sub c}, consistent with a strong enhancement of local magnetic susceptibility {chi}{double_prime}({h_bar}{sub {omega}}) below T{sub c}. These results suggest that CEF excitations in the rare-earth oxypnictides can be used as a probe of spin dynamics in the nearby FeAs planes.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 944112
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 0031-900 Vol. 101; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRIC FIELDS
MAGNETIC SUSCEPTIBILITY
NEUTRONS
PROBES
SCATTERING
SPIN