Incommensurate spin-density wave and magnetic lock-in transition in CaFe4As3

P. Manuel; L. C. Chapon; I. S. Todorov; D. Y. Chung; J. -P. Castellan; S. Rosenkranz; R. Osborn; P. Toledano; M. G. Kanatzidis

doi:10.1103/PhysRevB.81.184402

Incommensurate spin-density wave and magnetic lock-in transition in CaFe4As3

Strongly Correlated Electrons 2011-06-30 v1

Authors: P. Manuel , L. C. Chapon , I. S. Todorov , D. Y. Chung , J. -P. Castellan , S. Rosenkranz , R. Osborn , P. Toledano , M. G. Kanatzidis

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Abstract

The magnetic structure for the newly discovered iron-arsenide compound \CaFeAs has been studied by neutron powder diffraction. Long-range magnetic order is detected below 85K, with an incommensurate modulation described by the propagation vector k=(0, $\delta$ ,0), $\delta\sim$ 0.39. Below $\sim$ 25K, our measurements detect a first-order phase transition where $\delta$ 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 \textit{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.

Keywords

magnetic structure frustrated magnetism magnetic materials and spin systems

Cite

@article{arxiv.1002.1336,
  title  = {Incommensurate spin-density wave and magnetic lock-in transition in CaFe4As3},
  author = {P. Manuel and L. C. Chapon and I. S. Todorov and D. Y. Chung and J. -P. Castellan and S. Rosenkranz and R. Osborn and P. Toledano and M. G. Kanatzidis},
  journal= {arXiv preprint arXiv:1002.1336},
  year   = {2011}
}

Incommensurate spin-density wave and magnetic lock-in transition in CaFe4As3

Abstract

Keywords

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