Antiferromagnetic critical fluctuations in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>BaFe</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mtext>As</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>

Wilson, Stephen D.; Yamani, Z.; Rotundu, C. R.; Freelon, B.; Valdivia, P.; Bourret-Courchesne, Edith; Lynn, J. W.; Chi, Songxue; Hong, Tao; Birgeneau, R. J.

doi:10.1103/physrevb.82.144502

Cited by 19 publications

(19 citation statements)

References 25 publications

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“…At slightly lower energies, a gapped excitation is observed near Q = 0. [61]. Unlike the crystal field excitation, this scattering is well-defined in momentum and decays quickly with momentum transfer, bearing a strong resemblance to the magnetic excitation observed in powder averaged measurements of La 2 O 2 Fe 2 OSe 2 [49].…”

Section: B Inelastic Neutron Scatteringmentioning

confidence: 99%

Magnetism of theFe2+andCe3+sublattices inCe2<

et al. 2014

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The discovery of superconductivity in the 122 iron selenide materials above 30 K necessitates an understanding of the underlying magnetic interactions. We present a combined experimental and theoretical investigation of magnetic and semiconducting Ce2O2FeSe2 composed of chains of edgelinked iron selenide tetrahedra. The combined neutron diffraction and inelastic scattering study and density functional calculations confirm the ferromagnetic nature of nearest-neighbour Fe -Se -Fe interactions in the ZrCuSiAs-related iron oxyselenide Ce2O2FeSe2. Inelastic measurements provide an estimate of the strength of nearest-neighbor Fe -Fe and Fe -Ce interactions. These are consistent with density functional theory calculations, which reveal that correlations in the Fe-Se sheets of Ce2O2FeSe2 are weak. The Fe on-site repulsion UF e is comparable to that reported for oxyarsenides and K1−xFe2−ySe2, which are parents to iron-based superconductors.

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Section: B Inelastic Neutron Scatteringmentioning

confidence: 99%

Magnetism of theFe2+andCe3+sublattices inCe2<

et al. 2014

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“…[94][95][96] Both sets of experiments on BaFe 2 As 2 showed the presence of the AFM spin correlations at T>T N . The persistence of the AFM precursor associated with the SDW instability in OPD compounds was demonstrated in nuclear magnetic resonance (NMR) experiments.…”

Section: Infrared Pseudogap Antiferromagnetic Fluctuations and Amentioning

confidence: 99%

Infrared pseudogap in cuprate and pnictide high-temperature superconductors

et al. 2014

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Japan 2We investigate infrared manifestations of the pseudogap in the prototypical cuprate and pnictide superconductors: YBa 2 Cu 3 O y and BaFe 2 As 2 (Ba122) systems. We find remarkable similarities between the spectroscopic features attributable to the pseudogap in these two classes of superconductors. The hallmarks of the pseudogap state in both systems include a weak absorption feature at about 500 cm -1 followed by a featureless continuum between 500 and 1500 cm -1 in the conductivity data and a significant suppression in the scattering rate below 700 -900 cm -1 . The latter result allows us to identify the energy scale associated with the pseudogap  PG . We find that in the Ba122-based materials the superconductivity-induced changes of the infrared spectra occur in the frequency region below 100 -200 cm -1 , which is much lower than the energy scale of the pseudogap. We performed theoretical analysis of the scattering rate data of the two compounds using the same model which accounts for the effects of the pseudogap and electron-boson coupling. We find that the scattering rate suppression in Ba122-based compounds below  PG is solely due to the pseudogap formation whereas the impact of the electron-boson coupling effects is limited to lower frequencies. The magnetic resonance modes used as inputs in our modeling are found to evolve with the development of the pseudogap, suggesting an intimate correlation between the pseudogap and magnetism.

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“…Sensitivity of magnetic order to fine-tuning of the lattice structure is surprising in light of (a) the strong firstorder nature of the magnetic transition, and (b) the widely held view that the structural transition that accompanies T 0 is driven by magnetic interactions (and not vise-versa) [1]. However, with critical scattering persisting up to temperatures high above T 0 [32], it is possible that magnetic interactions do play a primary role. But because there is no clear indication of local-moment type order (e.g., no direct relationship between ordering and any structural bond length, i.e., tuning J), it is tempting to assign the observed coupling between magnetic ordering and structure to details involving the electronic structure, in particular the nesting condition that is thought to favor magnetic ordering in the parent compounds and to play a vital role in optimizing superconductivity [33].…”

mentioning

confidence: 99%

Tuning magnetism in FeAs-based materials via a tetrahedral structure

et al. 2012

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Resistivity, magnetic susceptibility, neutron scattering and x-ray crystallography measurements were used to study the evolution of magnetic order and crystallographic structure in single-crystal samples of the Ba1−xSrxFe2As2 and Sr1−yCayFe2As2 series. A non-monotonic dependence of the magnetic ordering temperature T0 on chemical pressure is compared to the progression of the antiferromagnetic staggered moment, characteristics of the ordering transition and structural parameters to reveal a distinct relationship between the magnetic energy scale and the tetrahedral bond angle, even far above T0. In Sr1−yCayFe2As2, an abrupt drop in T0 precisely at the Ca concentration where the tetrahedral structure approaches the ideal geometry indicates a strong coupling between the orbital bonding structure and the stabilization of magnetic order, providing strong constraints on the nature of magnetism in the iron-arsenide superconducting parent compounds.

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Antiferromagnetic critical fluctuations inBaFe2As2

Cited by 19 publications

References 25 publications

Magnetism of theFe2+andCe3+sublattices inCe2<

Magnetism of theFe2+andCe3+sublattices inCe2<

Infrared pseudogap in cuprate and pnictide high-temperature superconductors

Tuning magnetism in FeAs-based materials via a tetrahedral structure

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