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Jorda, J. L.; Hopfinger, Th.; Couach, M.; Pugnat, P.; Bertrand, Ch.; Galez, Ph.

doi:10.1023/a:1022602517307

Cited by 13 publications

(9 citation statements)

References 6 publications

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“…Grain growth is observed after an annealing of the film at 850°C in oxygen atmosphere. In agreement with the phases equilibria studies [4,5], BaCu02 and Ca2Cu03 phases have been found to coexist.…”

Section: Deposition Of Precursorssupporting

confidence: 88%

“…Following the procedure established in previous works [4,5], the precursor layers have been thallinated at 900°C, during 3 hours, in a sealed quartz tube under an oxygen pressure of 0.5 bar. In order to produce T1-1223, the thallium source, here, is a bulk sample (300 mg) with a nominal composition T1-1223, prepared by annealing of a mixture of oxides at 800°C under oxygen flow, during 6 hours.…”

Section: Experimental and Analysismentioning

confidence: 99%

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Critical parameters for the preparation of TI-1223 superconducting films by spray pyrolysis

et al. 2001

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Abstract. Thick films of the high temperature T1Ba2Ca2Cu30, superconductor have been prepared from a precursor Ba2Ca2Cu30, obtained by spray pyrolysis. In this paper, we report on the parameters which mainly control the formation of the superconducting phase: the composition of the nitrates solution, the substrate temperature and the subsequent ex-situ thallination annealing. The sample were analyzed by X-ray diffraction and by secondary electron microscopy. Epitaxial film ( 1 to 2 pm thick ) with a critical temperature Tc=107 K and a critical density of current J,(77 K, 0~) = 2 . 1 0~ ,Wcm2 have been obtained.

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Section: Deposition Of Precursorssupporting

confidence: 88%

Section: Experimental and Analysismentioning

confidence: 99%

Critical parameters for the preparation of TI-1223 superconducting films by spray pyrolysis

et al. 2001

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“…Various structural polymorphs simultaneously occur in Tl-based cuprates as lower members (n<3) form at an early stage of growth before converting to higher phase (n3) especially in the case of Tl-1223 and Tl-2223 [19][20][21]. Slight variations in the bulk composition, though not detectable in the XRD patterns (slightly broaden Bragg peak; oxygen insensitivity), may coexist with desired composition and affect the deterioration or broadening of the superconducting transition [19].…”

Section: Introductionmentioning

confidence: 99%

Structural and superconducting features of Tl-1223 prepared at ambient pressure

Shipra

Idrobo

Sefat

2015

Supercond. Sci. Technol.

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This study provides an account of the bulk preparation of TlBa 2 Ca 2 Cu 3 O 9−δ (Tl-1223) superconductor at ambient pressure, and the critical temperature (T c ) features under thermalannealing conditions. The 'as-prepared' Tl-1223 (T c =106 K) presents a significantly higher T c =125 K after annealing the polycrystalline material in either flowing Ar+4% H 2 , or N 2 gases. In order to understand the fundamental reasons for a particular T c , we refined the average bulk structures using powder x-ray diffraction data. Although Ar+4%H 2 annealed Tl-1223 shows an increased 'c' lattice parameter, it shrinks by 0.03% (approximately unchanged) upon N 2 anneal. Due to such indeterminate conclusions on the average structural changes, local structures were investigated at using aberration-corrected scanning-transmission electron microscopy technique. Similar compositional changes in the atomic arrangements of both annealed-samples of Tl-1223 were detected in which the plane containing a Ca atomic layer gives a non-uniform contrast, due to substitution of some heavier Tl. In this report, extensive bulk properties are summarized through temperature-dependent resistivity, and shielding and Meissner fractions of magnetic susceptibility results; the bulk and local structures are investigated to correlate to properties.

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“…Its crystal structure shows lower anisotropy than other Bi-and Tl-based phases. The presence of only a single Tl-O insulating (charge-reservoir) layer leads to a better coupling between the Cu-O 2 layers, therefore the irreversibility line is highly positioned, the critical currents are less temperature and magnetic field dependent and the magnetic flux pinning ability is high [1][2][3]. However, the preparation of 213 Unauthenticated Download Date | 5/13/18 9:54 AM pure mono-phase compounds is quite difficult.…”

Section: Introductionmentioning

confidence: 99%

“…Gritzner et al [15] 2 Cu 3 O 8+δ (0 < x < 0.1) system were studied in [16]. Based on XRD results, dominant content of the (Tl,Pb)-1223 phase was found in all samples.…”

Section: Introductionmentioning

confidence: 99%

Effects of low-level La doping and ageing on TlPb-1223 high T c superconductors

et al. 2010

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Abstract:Bulk samples of the nominal composition of (Tl 0.6 Pb 0.5 )(Sr 0.8 Ba 0.2 ) 2 Ca 2 Cu 3 O 8+δ -xLaO 1.5 (x = 0 − 0.1) were prepared by using two-step process and their microstructure, T c values, and magnetization were studied. The samples consist of the Tl-1223 dominant phase with small Tl-1212 admixture, which increases with a rise of La content. Five years ageing and following oxygen annealing at 450°C and subsequently at 750°C have only a modest effect on T c values of the studied samples. Low-level La doping (x = 0.04) leads to an increase of T c values by about 2 K in comparison with undoped samples. Oxygen annealing at 750°C results in an increase in the volume magnetization hysteresis in low applied magnetic fields and rise of critical current density at zero magnetic field and 77 K. This effect is most pronounced for the low La doped sample with x = 0.04. Changes of the induced voltage, U originating in the Meissner effect and of its harmonics in dependence on temperature were measured and used for characterization of the temperature distribution of inter-grain junctions.

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Cited by 13 publications

References 6 publications

Critical parameters for the preparation of TI-1223 superconducting films by spray pyrolysis

Critical parameters for the preparation of TI-1223 superconducting films by spray pyrolysis

Structural and superconducting features of Tl-1223 prepared at ambient pressure

Effects of low-level La doping and ageing on TlPb-1223 high T c superconductors

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