Spin excitations in the antiferromagnet<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Na</mml:mi><mml:mi mathvariant="normal">Ni</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>

Brion, S. de; Darie, Céline; Holzapfel, Michael; Talbayev, Diyar; Mihály, L.; Simón, F.; Jànossy, A.; Chouteau, G.

doi:10.1103/physrevb.75.094402

Cited by 15 publications

(16 citation statements)

References 23 publications

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“…[1][2][3][4][5][6][7][8][9][10][11] Among them, delafossite oxides containing Ni 3+ ions are good examples to observe rich and complex magnetic properties. [4][5][6][7][8][9][10][11] In these materials, each magnetic Ni 3+ ion ͑t 2g 6 e g 1 ͒ is surrounded by six oxygen ions, and the threefold symmetry is established among three tilted octahedra sharing a vertex. Therefore, their lattices provide possibilities not only for magnetic but even charge or orbital frustrations, leading to various forms of electronic and/or magnetic order.…”

Section: Introductionmentioning

confidence: 99%

Possible charge disproportionation in3R-AgNiO2studied by neutron powder diffraction

et al. 2008

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Using neutron-scattering techniques, we have investigated the nuclear and the magnetic structures of the triangular antiferromagnet 3R-AgNiO 2 . The symmetry analysis based on the group theory suggests that the ͱ 3 ϫ ͱ 3 charge order proposed for 2H-AgNiO 2 ͓E. Wawrzyńska et al., Phys. Rev. Lett. 99, 157204 ͑2007͔͒will have a monoclinic symmetry if present in the trigonal lattice of 3R-AgNiO 2 . The Rietveld refinement shows that symmetry reduction in the NiO 2 layer is consistent with the prediction of the group theory. The pair density function consistently shows that the nearest-neighbor Ni-O bonds split into two groups separated by approximately 0.1 Å. The antiferromagnetic Bragg peaks observed below T N = 25 K can be described by the propagation vector k = ͑0,1,0͒ of the monoclinic unit cell. The similarities of the local structure and the antiferromagnetic order strongly suggest that the novel charge order observed in 2H-AgNiO 2 also exists in 3R-AgNiO 2 .

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Section: Introductionmentioning

confidence: 99%

Possible charge disproportionation in3R-AgNiO2studied by neutron powder diffraction

et al. 2008

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“…In addition, recent experiments have reported the complex ground state in some kindred compounds Na x MO 2 ͑M =Ni,Cr͒. [15][16][17] So experimental investigations of the hexagonal compound Na 0.70 MnO 2 will shed light on the understanding of the family compounds of sodium transition-metal oxides.…”

Section: Introductionmentioning

confidence: 99%

Spin-glass behavior in hexagonalNa0.70MnO2

et al. 2007

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In this paper, we present an experimental study of the hexagonal compound Na 0.70 MnO 2 . Zero-field-cooled and field-cooled susceptibilities display divergences at low temperatures, and the magnetic measurements of frequency dependence of ac susceptibility, hysteresis effect, and long-time relaxation are performed, indicating that Na 0.70 MnO 2 undergoes a spin-glass transition at T f = 39 K. The spin-glass order parameter q͑T͒ determined from the dc spin susceptibility exhibits the relation q͑T͒ ϰ ͑1−T / T f ͒, in agreement with the prediction of conventional spin-glass theory. Spin dynamics in the spin-glass state is carefully examined, and the time decay of the thermoremanent magnetization can be well scaled with a reduced effective waiting time / t w . The magnetic entropy extracted from the specific heat implies that the spin degrees of freedom of Mn 3+ /Mn 4+ ions are completely frozen at low temperatures, and the origin of this spin-glass behavior is attributed to the mixture of Mn 3+ /Mn 4+ ions and geometrical frustrations on the triangular lattices. Comparisons with the magnetic properties of Na 0.70 CoO 2 are also made.

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“…Some of the first results for LaMnO 3 , a well-known antiferromagnet and the parent compound of the so-called colossal magnetoresistance materials, are shown in Figure 6 [38,39]. Other projects currently in progress include the study of the single molecular magnet Mn 12 -acetate, spin resonance on NaNiO 2 [40], the investigation of correlated magnetic systems including LiCu 2 O 2 and others [41], and magneto-optical studies on superconductors, including carbon-doped MgB 2 .…”

Section: Technical Reportsmentioning

confidence: 96%