Frontiers of Physics in China

, Volume 5, Issue 2, pp 161–165

Low-energy Ce spin excitations in CeFeAsO and CeFeAsO0.84F0.16

  • Shi-liang Li (李世亮)
  • Dao-xin Yao (姚道新)
  • Yi-ming Qiu (邱义铭)
  • Hye Jung Kang
  • E. W. Carlson
  • Jiang-ping Hu (胡江平)
  • Gen-fu Chen (陈根富)
  • Nan-lin Wang (王楠林)
  • Peng-cheng Dai (戴鹏程)
Research Article

DOI: 10.1007/s11467-009-0077-8

Cite this article as:
Li, S., Yao, D., Qiu, Y. et al. Front. Phys. China (2010) 5: 161. doi:10.1007/s11467-009-0077-8

Abstract

We use inelastic neutron scattering to study the low-energy spin excitations of polycrystalline samples of nonsuperconducting CeFeAsO and superconducting CeFeAsO0.84F0.16. Two sharp dispersionless modes are found at 0.85 and 1.16 meV in CeFeAsO below the Ce antiferromagnetic (AF) ordering temperature of TNCe ˜ 4 K. On warming to above TNCe ˜ 4 K, these two modes become one broad dispersionless mode that disappears just above the Fe ordering temperature TNFe ˜ 140 K. For superconducting CeFeAsO0.84F0.16, where Fe static AF order is suppressed, we find a weakly dispersive mode center at 0.4 meV that may arise from short-range Ce-Ce exchange interactions. Using a Heisenberg model, we simulate powder-averaged Ce spin wave excitations. Our results show that we need both Ce spin wave and crystal electric field excitations to account for the whole spectra of low-energy spin excitations.

Keywords

iron pnictides rare earth spin waves crystal field 

PACS numbers

71.70.Ch 75.30.Ds 74.25.Ha 

Copyright information

© Higher Education Press and Springer Berlin Heidelberg 2010

Authors and Affiliations

  • Shi-liang Li (李世亮)
    • 1
    • 2
  • Dao-xin Yao (姚道新)
    • 3
  • Yi-ming Qiu (邱义铭)
    • 4
    • 5
  • Hye Jung Kang
    • 6
  • E. W. Carlson
    • 3
  • Jiang-ping Hu (胡江平)
    • 3
  • Gen-fu Chen (陈根富)
    • 7
  • Nan-lin Wang (王楠林)
    • 1
  • Peng-cheng Dai (戴鹏程)
    • 2
    • 8
    • 1
  1. 1.Beijing National Laboratory for Condensed Matter Physics, Institute of PhysicsChinese Academy of SciencesBeijingChina
  2. 2.Department of Physics and AstronomyThe University of TennesseeKnoxvilleUSA
  3. 3.Department of PhysicsPurdue UniversityWest LafayetteUSA
  4. 4.NIST Center for Neutron ResearchNational Institute of Standards and TechnologyGaithersburgUSA
  5. 5.Department of Materials Science and EngineeringUniversity of MarylandCollege ParkUSA
  6. 6.Department of Physics and AstronomyClemson UniversityClemsonUSA
  7. 7.Department of PhyiscsRenmin University of ChinaBeijingChina
  8. 8.Neutron Scattering Sciences DivisionOak Ridge National LaboratoryOak RidgeUSA

Personalised recommendations