Magnetic ordering and spin waves in $\bf Na_{0.82}CoO_2$

S. P. Bayrakci; I. Mirebeau; P. Bourges; Y. Sidis; M. Enderle; J. Mesot; D. P. Chen; C. T. Lin; B. Keimer

doi:10.1103/PhysRevLett.94.157205

Magnetic ordering and spin waves in $\bf Na_{0.82}CoO_2$

Strongly Correlated Electrons 2009-11-10 v2 Superconductivity

Authors: S. P. Bayrakci , I. Mirebeau , P. Bourges , Y. Sidis , M. Enderle , J. Mesot , D. P. Chen , C. T. Lin , B. Keimer

View on arXiv ↗ PDF ↗ DOI ↗

Abstract

Na $_x$ CoO $_2$ , the parent compound of the recently synthesized superconductor Na $_x$ CoO $_2$ : $y$ H $_2$ O, exhibits bulk antiferromagnetic order below $\sim20$ K for 0.75 $\leq x \leq$ 0.9. We have performed neutron scattering experiments in which we observed Bragg reflections corresponding to A-type antiferromagnetic order in a Na $_{0.82}$ CoO $_2$ single crystal and characterized the corresponding spin-wave dispersions. The spin waves exhibit a strongly energy-dependent linewidth. The in-plane and out-of-plane exchange constants resulting from a fit to a nearest-neighbor Heisenberg model are similar in magnitude, which is unexpected in view of the layered crystal structure of Na $_{x}$ CoO $_2$ . Possible implications of these observations are discussed.

Keywords

antiferromagnetic order spin waves neutron scattering NaCoO2 exchange constants Heisenberg model

Cite

@article{arxiv.cond-mat/0410224,
  title  = {Magnetic ordering and spin waves in $\bf Na_{0.82}CoO_2$},
  author = {S. P. Bayrakci and I. Mirebeau and P. Bourges and Y. Sidis and M. Enderle and J. Mesot and D. P. Chen and C. T. Lin and B. Keimer},
  journal= {arXiv preprint arXiv:cond-mat/0410224},
  year   = {2009}
}

Comments

final version, to appear in PRL

Magnetic ordering and spin waves in $\bf Na_{0.82}CoO_2$

Abstract

Keywords

Cite

Comments

Related papers