Influence of sintering conditions in the preparation of acetate-based fluorine-free CSD YBCO films using a direct sintering method

Vermeir, Pieter; Feys, Jonas; Schaubroeck, J.; Verbeken, Kim; Lommens, Petra; Driessche, Isabel Van

doi:10.1016/j.materresbull.2012.09.033

Cited by 24 publications

(16 citation statements)

References 28 publications

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“…The a -axis grains are film defects that will block current flowing in GdBCO films. They will cause the degradation of J c [12,13]. …”

Section: Resultsmentioning

confidence: 99%

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

Wang

et al. 2013

Nanoscale Res Lett

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GdBa2Cu3O7 − δ (GdBCO) films with different thicknesses from 200 to 2,100 nm are deposited on CeO2/yttria-stabilized zirconia (YSZ)/CeO2-buffered Ni-W substrates by radio-frequency magnetron sputtering. Both the X-ray diffraction and scanning electron microscopy analyses reveal that the a-axis grains appear at the upper layers of the films when the thickness reaches to 1,030 nm. The X-ray photoelectron spectroscopy measurement implies that the oxygen content is insufficient in upper layers beyond 1,030 nm for a thicker film. The Williamson-Hall method is used to observe the variation of film stress with increasing thickness of our films. It is found that the highest residual stresses exist in the thinnest film, while the lowest residual stresses exist in the 1,030-nm-thick film. With further increasing film thickness, the film residual stresses increase again. However, the critical current (Ic) of the GdBCO film first shows a nearly linear increase and then shows a more slowly enhancing to a final stagnation as film thickness increases from 200 to 1,030 nm and then to 2,100 nm. It is concluded that the roughness and stress are not the main reasons which cause the slow or no increase in Ic. Also, the thickness dependency of GdBa2Cu3O7 − δ films on the Ic is attributed to three main factors: a-axis grains, gaps between a-axis grains, and oxygen deficiency for the upper layers of a thick film.

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“…The a -axis grains are film defects that will block current flowing in GdBCO films. They will cause the degradation of J c [12,13]. …”

Section: Resultsmentioning

confidence: 99%

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

Wang

et al. 2013

Nanoscale Res Lett

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“…Indeed, the slow HF diffusion is the main challenge in obtaining cost-competitive YBCO tapes. Therefore, other precursor solutions have been considered, such as low-fluorine [2] or fluorine-free (FF) solutions [10]. In fact, it has been shown that, from FF solutions, YBCO can grow through a liquid-solid reaction [11,12], and this in turn can lead to very high growth rates.…”

Section: Introductionmentioning

confidence: 99%

Thermal decomposition of yttrium propionate: film and powder

Rasi

Ricart

Obradors

et al. 2018

Journal of Analytical and Applied Pyrolysis

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A B S T R A C TThe processes involved in the thermal decomposition of yttrium propionate in oxidizing and inert atmosphere were analyzed with thermoanalytical techniques (thermogravimetry and evolved gas analysis) and with the help of structural characterization (X-ray diffraction, infrared spectroscopy and elemental analysis) of intermediate and final products. Samples in the form of films and powders were analyzed. The decomposition behavior studied as a function of particle size and film thickness was investigated. We conclude that, as a consequence of the gas and heat transport, films decompose differently than powders. Finally, two decomposition mechanisms are proposed that are in agreement with the observed volatiles and intermediate phases.

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“…The formation mechanism of YBCO through intermediate liquid phases has been suggested to occur since long time ago by several authors and it has been recently confirmed . The rationale was to propose that, after decomposition of Ba carbonate, BaCuO 2 is formed and that, once above the eutectic temperature, T E , the BaCuO 2 ‐CuO liquid phase reacts with Y 2 O 3 .…”

Section: Discussionmentioning

confidence: 96%

Preparation of GdBa₂Cu₃O_6+x (GdBCO) precursor powder by spray‐drying a nitrate solution containing PEG

Camps

Farjas

Roura

et al. 2020

Int J Applied Ceramic Tech

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Several precursor powders, obtained after precipitation from metal nitrate solution containing polyethylene glycol (PEG) (inside a Pyrex glass reactor or by spray‐drying), and their thermal evolution to GdBa2Cu3O6+x (GdBCO) were analyzed by thermogravimetry, differential thermal analysis, Fourier‐transform infrared spectroscopy, and X‐ray diffraction. The amount of PEG had a crucial role in the BaCO3 content of the “Kjeldahl precursors,” but a minor effect on the degree of transformation to GdBCO at 900°C, which did not reach completion after 1 hour. In contrast, a low‐PEG spray‐dried powder led to almost 100% GdBCO in only 5 minutes. The high degree of cation dispersion reached by spray‐drying and the coexistence with a liquid phase can explain this short reaction time. The spray‐dried powder compares favorably with the mechanical mix of metal oxides and Ba carbonate that is commonly used as precursor powder for the synthesis following a solid‐state reaction.

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Influence of sintering conditions in the preparation of acetate-based fluorine-free CSD YBCO films using a direct sintering method

Cited by 24 publications

References 28 publications

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

Thermal decomposition of yttrium propionate: film and powder

Preparation of GdBa₂Cu₃O_6+x (GdBCO) precursor powder by spray‐drying a nitrate solution containing PEG

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Influence of sintering conditions in the preparation of acetate-based fluorine-free CSD YBCO films using a direct sintering method

Cited by 24 publications

References 28 publications

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

Thermal decomposition of yttrium propionate: film and powder

Preparation of GdBa2Cu3O6+x (GdBCO) precursor powder by spray‐drying a nitrate solution containing PEG

Contact Info

Product

Resources

About

Preparation of GdBa₂Cu₃O_6+x (GdBCO) precursor powder by spray‐drying a nitrate solution containing PEG