Structural characterization of new ternary compounds of uranium and cerium

Cordier, G.; Czech, E.; Schäfer, Helmut; Woll, P.

doi:10.1016/0022-5088(85)90340-6

Cited by 87 publications

(36 citation statements)

References 3 publications

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“…The obtained theoretical c / a ratio almost coincides with the experimental value ͑2.32͒. 7,85 The optimized c / a ratio of the LMAF phase is found to be just a small fraction larger than that of the PM phase. We note that x-ray diffraction experiments have been unable to detect any difference in the lattice constants of the PM, LMAF, and HO phases.…”

Section: Structural Optimizationsupporting

confidence: 76%

“…Several experimental investigations of the structural properties of URu 2 Si 2 have been reported. 7,[85][86][87] For comparison to the available data, we have performed ab initio optimizations of the equilibrium volume, the c / a ratio, and the internal Si coordinate, z Si . These optimizations have been performed on the LSDA level, both for the PM and LMAF phases.…”

Section: Structural Optimizationmentioning

confidence: 99%

“…7,85,87 As the LSDA approach is know to produce a small overbinding, the correspondence with the experimental lattice constant can be regarded as very good. The bct structure of URu 2 Si 2 has one internal coordinate, the Si z position.…”

Section: Structural Optimizationmentioning

confidence: 99%

“…5 we show the computed LSDA energy dispersions in the PM and LMAF phases for the experimental lattice parameters. 85 To draw a comparison, both sets of dispersions are given for the double unit cell ͑space group No. 123͒.…”

Section: Energy Band Dispersionsmentioning

confidence: 99%

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Electronic structure theory of the hidden-order materialURu2Si2

et al. 2010

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We report a comprehensive electronic structure investigation of the paramagnetic ͑PM͒, the large moment antiferromagnetic ͑LMAF͒, and the hidden order ͑HO͒ phases of URu 2 Si 2 . We have performed relativistic full-potential calculations on the basis of the density-functional theory, employing different exchangecorrelation functionals to treat electron correlations within the open 5f shell of uranium. Specifically, we investigate-through a comparison between calculated and low-temperature experimental properties-whether the 5f electrons are localized or delocalized in URu 2 Si 2 . The local spin-density approximation ͑LSDA͒ and generalized gradient approximation ͑GGA͒ are adopted to explore itinerant 5f behavior, the GGA plus additional strong Coulomb interaction ͑GGA+ U approach͒ is used to approximate moderately localized 5f states, and the 5f-core approximation is applied to probe potential properties of completely localized uranium 5f states. We also performed local-density approximation plus dynamical mean-field theory calculations ͑DMFT͒ to investigate the temperature evolution of the quasiparticle states at 100 K and above, unveiling a progressive opening of a quasiparticle gap at the chemical potential when temperature is reduced. A detailed comparison of calculated properties with known experimental data demonstrates that the LSDA and GGA approaches, in which the uranium 5f electrons are treated as itinerant, provide an excellent explanation of the available low-temperature experimental data of the PM and LMAF phases. We show furthermore that due to a materialspecific Fermi-surface instability a large, but partial, Fermi-surface gapping of up to 750 K occurs upon antiferromagnetic symmetry breaking. The occurrence of the HO phase is explained through dynamical symmetry breaking induced by a mode of long-lived antiferromagnetic spin fluctuations. This dynamical symmetry breaking model explains why the Fermi-surface gapping in the HO phase is similar but smaller than that in the LMAF phase and it also explains why the HO and LMAF phases have the same Fermi surfaces yet different order parameters. A suitable order parameter for the HO is proposed to be the Fermi-surface gap, and the dynamic spin-spin correlation function is further suggested as a secondary order parameter.

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Section: Structural Optimizationsupporting

confidence: 76%

Section: Structural Optimizationmentioning

confidence: 99%

Section: Structural Optimizationmentioning

confidence: 99%

Section: Energy Band Dispersionsmentioning

confidence: 99%

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Electronic structure theory of the hidden-order materialURu2Si2

et al. 2010

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“…As Ln progresses from Ce to Sm, the Sb-Sb interatomic distances decrease. Perfectly square sheets have been found for the LnT x Sb 2 (T=Mn, Fe, Co, Ni, Cu, Zn, Pt, Pd, Cd, Ag, Au) compounds, where x is usually less than or equal to 1 [16][17][18][19][20][21][22][23]. The Sb-Sb-Sb angles in LnNiSb 3 (Ln=Ce-Nd, Sm) deviate from 901, further indicating distorted Sb nearly square nets.…”

Section: Structurementioning

confidence: 99%