Structure of Tetragonal YBa2Cu3O5.8

Katano, Susumu; Funahashi, Satoru; Hatano, Takeshi; Matsushita, A.; Nakamura, Keikichi; Matsumoto, Takehiko; Ogawa, Keiichi

doi:10.1143/jjap.26.l1049

Cited by 43 publications

(12 citation statements)

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“…Our main interest, however, concerns the modulation frequency, int . And this value is not critically affected by details of the form of I (2). For instance, instead of using Eq.…”

Section: B the Internal Field At The Ba Sitementioning

confidence: 99%

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Hyperfine fields at the Ba site in the antiferromagnet YBa2Cu3<

et al. 1996

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We report a Ba nuclear quadrupole resonance ͑NQR͒ study of the antiferromagnetic state of YBa 2 Cu 3 O 6.05 ͑Néel temperature T N ϭ 415 K͒ performed between 16 and 402 K. The Zeeman perturbed 137 Ba NQR spectrum yields information on two hyperfine fields present at the Ba site: the electric field gradient ͑EFG͒ and the internal magnetic field arising from the Cu͑2͒ sublattice magnetization. The absolute value of the EFG is in remarkable agreement with cluster and band structure calculations thus demonstrating again that both methods provide a satisfying electronic bond picture for the Y-Ba-Cu-O compounds ͓except for the planar Cu͑2͒ site͔. The temperature dependence of the EFG arises from thermal expansion only. The internal field, B(T), has been deduced from the modulation of the Ba spin-echo intensity. A calculation of the dipolar field at the Ba site produced by Cu͑2͒ d electrons yields a value that is about three times larger than the experimental result. The discrepancy could be explained by assuming that part of the magnetic moment is located at oxygen ions. The temperature variation of B(T) follows, up to 402 K, a power law ͓B(0)ϪB(T)͔/B(0)ϭAT ␣ with ␣ ϭ 1.82͑22͒ which agrees quite well with the result of a Cu͑2͒ in-plane determination of the sublattice magnetization. Furthermore, this result is in accord with a spin-wave model for a quasi-two-dimensional ͑2D͒ antiferromagnet. The ''critical exponent'' ␤ is estimated to be р 0.18 which is in accord with values proposed by models for 2D ordered magnetic systems. Thus YBa 2 Cu 3 O 6.05 behaves, in terms of its spin dynamics, as a quasi-2D antiferromagnet and this character can be studied either at out-ofplane Ba or at in-plane Cu͑2͒ sites.

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“…Our main interest, however, concerns the modulation frequency, int . And this value is not critically affected by details of the form of I (2). For instance, instead of using Eq.…”

Section: B the Internal Field At The Ba Sitementioning

confidence: 99%

“…For instance, instead of using Eq. ͑8͒, the data may be fitted with a function like I (2) ϰexp(Ϫ2/T 2 ٞ)͓1 ϩKЈcos(2 int )]. Although this fit is not as perfect as that provided by Eq.…”

Section: B the Internal Field At The Ba Sitementioning

confidence: 99%

Hyperfine fields at the Ba site in the antiferromagnet YBa2Cu3<

et al. 1996

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“…1, which includes data for systems having one apical O site (YBa 2 Cu 3 O 6 ), two apical O's (La 2 CuO 4 , HgBa 2 CuO 4 ), two apical Cl ions (Ca 2 CuO 2 Cl 2 , Sr 2 CuO 2 Cl 2 ) or no apical ligand (CaCuO 2 ). The apical Cu-O distances in La 2 CuO 4 and YBa 2 Cu 3 O 6 , for example, are nearly the same, 2.40 vs. 2.45Å [19,20,22]. In YBa 2 Cu 3 O 6 , however, there is a single apical O.…”

mentioning

confidence: 92%

Ab Initio determination of Cu 3d orbital energies in layered copper oxides

Hozoi

Siurakshina

Fulde

et al. 2011

Sci Rep

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It has long been argued that the minimal model to describe the low-energy physics of the high Tc superconducting cuprates must include copper states of other symmetries besides the canonical one, in particular the orbital. Experimental and theoretical estimates of the energy splitting of these states vary widely. With a novel ab initio quantum chemical computational scheme we determine these energies for a range of copper-oxides and -oxychlorides, determine trends with the apical Cu–ligand distances and find excellent agreement with recent Resonant Inelastic X-ray Scattering measurements, available for La2CuO4, Sr2CuO2Cl2, and CaCuO2.

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“…The crystal structure data of the tetragonal plase [11] are listed in Table. Although the lattice constants are very similar to those of CaYΑlO4 (CYA), the crystal structure itself is quite different. The YBCO crystal structure for x = 0 (Fig.…”

Section: Crystal Structurementioning

confidence: 99%

Growth Morphology and Atomic Surface Topology by Hartman-Perdok Analysis: Application to ABCO₄and YBa₂Cu₃O_7-x

Woensdregt

1997

Acta Phys. Pol. A

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The lfartman-Perdok theory explains the relation between crystal structure and morphology and provides the atomic surface topology of the crystalmelt interface. Hartman-Perdok theory has been applied to CaYΑIO 4 as model for all other ΑBCO 4 compounds with a K 2 ΝiF4 crystal structure. F forms are {002}, {101}, {103}, {110}, {112}, {200}, {211} and {213}. The strongly anisotropic shape caused by the perovskite-like ΑIO 6 layers | | (001) is very distinct in all theoretical growth forms. The form with formal charges is planar following {001} with (101) and {110) as 1ateral forms. Disordering of the boundary ions results in the disappearance of {110}. At lower effective charge on oxygen ions, qo, the ordered forms are still tabular, while (110) and (112) are the only lateral faces. At still lesser negative qo {112} appears as well. On the disordered models {112} replaces {110}. Crystals show often variations in colour parallel to the {110} interface due to the surface topology of {110}. YBa2Cu3O7-x has, for x = 1, the following F forms: {001}, {101}, {103}, {112} and {114}. The theoretical growth form of this tetragonal phase is tabular following {001} with {101} as lateral form. For x = 0 the growth form shows important {101} and minor {103} and {001}. When the boundary ions on (001) are ordered, the outermost layer of {001} contains half of the Cu+ (x = 1) or Cu3+ and O 2-(x = 0) ions in a c(2 x 2) quadratic lattice which reduces tle {001} growth rate significantly. An (1 x 2) reconstriicted {010} surface can be traced for the orthorhombic polymorph which results into the appearance of {010} oii the ordered growth form. Otherwise the presence of {010) on as-grown crystals must be due to external factors.PACS numbers: 68.35. Bs, 81.10.Aj Hartman-Perdok theoryThe relation between the internal crystal structure and the crystal morphology can be established by the ^Iartman-Perdok theory [1][2][3]. At the same time the surface topology of the crystalline interface can be derived at atomic scale.The crystal morphology is not only determined by internal factors such as crystal structure, twinning, dislocations, etc., but also by external factors such (35)

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Structure of Tetragonal YBa₂Cu₃O_5.8

Abstract: It is shown that the four-particle amplitude of superstring theory at two loops obtained in [1, 2] is equivalent to the previously obtained results in [3]- [5]. Here the Z 2 symmetry in hyperelliptic Riemann surface plays an important role in the proof.

Cited by 43 publications

References 10 publications

Hyperfine fields at the Ba site in the antiferromagnet YBa2Cu3<

Hyperfine fields at the Ba site in the antiferromagnet YBa2Cu3<

Ab Initio determination of Cu 3d orbital energies in layered copper oxides

Growth Morphology and Atomic Surface Topology by Hartman-Perdok Analysis: Application to ABCO₄and YBa₂Cu₃O_7-x

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Structure of Tetragonal YBa2Cu3O5.8

Abstract: It is shown that the four-particle amplitude of superstring theory at two loops obtained in [1, 2] is equivalent to the previously obtained results in [3]- [5]. Here the Z 2 symmetry in hyperelliptic Riemann surface plays an important role in the proof.

Cited by 43 publications

References 10 publications

Hyperfine fields at the Ba site in the antiferromagnet YBa2Cu3<

Hyperfine fields at the Ba site in the antiferromagnet YBa2Cu3<

Ab Initio determination of Cu 3d orbital energies in layered copper oxides

Growth Morphology and Atomic Surface Topology by Hartman-Perdok Analysis: Application to ABCO4and YBa2Cu3O7-x

Contact Info

Product

Resources

About

Structure of Tetragonal YBa₂Cu₃O_5.8

Growth Morphology and Atomic Surface Topology by Hartman-Perdok Analysis: Application to ABCO₄and YBa₂Cu₃O_7-x