Charge transfer process in Tl2Ba2Ca2Cu3O10 and Tl2Ba2CaCu2O8 thin films probed by polarized X-ray absorption spectroscopy

Chen, J. M.; Liu, R. G.; Liu, R. S.; Lin, Horng-Chih; Uen, T. M.; Juang, Jenh‐Yih; Gou, Y. S.

doi:10.1016/s0009-2614(97)00845-2

Cited by 2 publications

(6 citation statements)

References 22 publications

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“…The assignment of the first pre-edge peak at 528.6 eV for the O(1) and O(1) agrees with local density-of-states calculations (LDA) of Tl-2223 by Marksteiner et al and also agrees with several authors for various Tl-based, Hgbased and Bi-based superconductors as these systems have similar structures [31,32,36]. Following the same reasoning and utilizing the results of the LAD calculations [36], we can ascribe the second pre-edge feature at 529.4 eV with the O 2p holes in O(2) site of the Sr-O planes.…”

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemsupporting

confidence: 90%

“…The assignment of this peak to the O 2p xy symmetry rather than the out-of-plane O 2p z symmetry is confirmed by several polarization studies [14,[34][35][36][37]. Chen et al, for example found that the intensity of this pre-edge peak in Tl-2223 decreases with increasing the polarized light's incident angle with the c axis [31]. The intensity of this peak in figure 2, slightly increases with increasing fluorine content up to an optimum value of x, as shown in figure 3.…”

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemmentioning

confidence: 66%

“…The intensity of this peak increased on going from E1|ab to E1|c polarization, i.e. this peak has O 2P z symmetry [31,34].…”

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemmentioning

confidence: 94%

“…The spectral features above 535 eV reveal information about the local density of unoccupied states corresponding to O 2p states hybridized with Cu 4sp and Ba/Ca intermixing [34][35][36][37][38][39]. HgPb-1223 has four nonequivalent oxygen sites: O(1) and O(1) within the CuO 2 layers of the square planner and pyramidal arrangements, respectively, O(2) in the Ba-O and O(3) in the Hg-O planes [26,31,32,36].…”

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemmentioning

confidence: 99%

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Hole doping in high temperature superconductors using the XANES technique

Hamdan¹,

Hussain²

2009

Supercond. Sci. Technol.

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Superconducting and physical properties of F-doped HgPb-1223 and Ce-doped Tl-1223 systems were considerably improved through adjusting the hole content of the two systems. In this study, we have used the x-ray absorption near-edge structure (XANES) technique to investigate the electronic structure of the two systems by probing the unoccupied electronic states. For the F-doped Hg-1223 system, the O K-edge, Ca L 2,3 and Cu L 2,3 -edge structures were thoroughly investigated. The pre-edge features of O K-edge spectra, as a function of doping, reveal important information about the projected local density of unoccupied states on the O sites in the region close to the absorption edge, which is a measure of O 2p hole concentration in the valence band. In the originally under-doped Hg-1223, the results indicate that the number of O 2p holes in the CuO 2 planes increases as fluorine was introduced up to an optimal value, after which it decreases. Furthermore, the Cu L 2,3 absorption edge provides useful information about the valence state of Cu which is also related to the hole density in the CuO 2 planes and confirms the same previous conclusion. The Ca L 2,3 -edge shows the presence crystal field splitting in HgPb1223/F x which is similar to CaF 2 and CaO in addition to the spin-orbit splitting of the Ca 2p core level electrons. These results ensure that fluorine goes into the structure of HgPb-1223/F x and it occupies the vacant interstitial oxygen site in the Hg-O plane, as was expected. In Ce-substituted Tl-1223, similar measurements were performed for samples with different Ce content. The pre-edge feature of the O K-edge spectra shows clearly the drastic decrease of the hole content in CuO 2 planes of this originally over-doped system with increasing Ce content. This result is also confirmed from the chemical state of Ce in the structure as obtained from the Ce M 4,5 -edge spectra.

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Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemsupporting

confidence: 90%

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemmentioning

confidence: 66%

“…The intensity of this peak increased on going from E1|ab to E1|c polarization, i.e. this peak has O 2P z symmetry [31,34].…”

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemmentioning

confidence: 94%

Section: Anion Substitution (Fluorine For Oxygen) In Hg-pb-12223 Systemmentioning

confidence: 99%

See 2 more Smart Citations

Hole doping in high temperature superconductors using the XANES technique

Hamdan¹,

Hussain²

2009

Supercond. Sci. Technol.

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show abstract

“…In the first step, the Tl-free precursor is deposited on the substrate. Many deposition methods have been reported, for example sputtering [1][2][3], laser ablation [4,5], thermal evaporation [6] and organic chemical vapour deposition [7,8]. The chemical solution routes of the deposition-like spray pyrolysis [9,10] are preferred for preparing large-scale coatings in industry because of easier production and their low capital costs.…”

Section: Introductionmentioning

confidence: 99%