Incommensurate spin-density wave and magnetic lock-in transition in CaFe{sub 4}As{sub 3}.
The magnetic structure for the recently synthesized iron-arsenide compound CaFe4As3 has been studied by neutron-powder diffraction. Long-range magnetic order is detected below 85 K, with an incommensurate modulation described by the propagation vector k=(0,?,0), ??0.39. Below ?25 K, our measurements detect a first-order phase transition where ? locks into the commensurate value 3/8. A model of the magnetic structure is proposed for both temperature regimes, based on Rietveld refinements of the powder data and symmetry considerations. The structures correspond to longitudinal spin-density waves with magnetic moments directed along the b axis. A Landau analysis captures the change in thermodynamic quantities observed at the two magnetic transitions, in particular, the drop in resistivity at the lock-in transition.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- SC
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 982678
- Report Number(s):
- ANL/MSD/JA-66286
- Journal Information:
- Phys. Rev. B, Journal Name: Phys. Rev. B Journal Issue: May 1, 2010 Vol. 81; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- ENGLISH
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