Complexation behavior in aqueous edta sol-gel systems for the synthesis of YBa2Cu3O7-x high-temperature superconductors

Abstract

Duas soluções à base de água contendo precursores do óxido YBa 2 Cu 3 O 7-x e utilizando edta (ácido etilenodiaminotetra-acético) como agente complexante são apresentadas. Estes precursores foram usados na deposição de camadas finas de materiais supercondutores de altas temperaturas (HTSC). A influência do comportamento da complexação na formação de soluções e de géis transparentes e homogêneos após a combinação de acetatos de metais e outros modificadores foi estudada, comparada e interpretada utilizando equilíbrios metal-ligante. A ocorrência de diferentes espécies químicas em diferentes valores de pH pode estar relacionada às condições de formação de géis estáveis. Os precursores foram utilizados na deposição de filmes finos supercondutores texturizados por dip coating. A análise por difratometria de raios X de pó (XRD) indicou que uma única fase YBCO (óxido de ítrio, bário e cobre) foi obtida. A técnica de espectroscopia no infravermelho por refletância total atenuada (ATR-FTIR) foi utilizada para determinar o nível de carbono residual nos materiais YBCO finais, que foi menor do que 0,01%.Two water-based YBa 2 Cu 3 O 7-x precursor solutions using edta (ethylenediaminetetraacetic acid) as complexing agent are presented. These precursors were employed to deposit thin layers of high-temperature superconducting (HTSC) materials. The influence of the complexation behavior on the formation of transparent and homogeneous solutions and gels after the combination of metal acetates and other modifiers was studied, compared and interpreted using metal-ligand equilibria. The occurrence of different chemical species at different pH values appears to be related to stable gel formation conditions. It is found that both acetic acid and edta play an important role in controlling the condensation reaction to form a continuous network polymer. The precursors were used to deposit textured superconducting thin films on SrTiO 3 (STO) substrates by dip coating. Analysis by X-ray diffractometry (XRD) indicated that a single YBCO (yttrium barium copper oxide) phase was obtained. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to determine the carbon residue level in the YBCO final materials, which was lower than 0.01%.

The Synthesis of YBa₃Cu₄O_x Superconductor and Comparison with YBa₂Cu₃O_x

“…The FTIR measurements, we found peak at 2922, 1440 cm -1 in all samples its correspond with Thuy & et al [8] is the reflection at 2800-3000 cm -1 is typical for C-H stretching showing the remainders of organic compounds in samples and the region of 1400-1500 cm -1 is a peak due to a C=O stretch showing the contained carbonate residues in YBCO samples.…”

Optimization of Copper Stain Removal from Marble through the Formation of Cu(II) Complexes in Agar Gels

“…In order to study complex stability with pH in a free aqueous solution, the absorbance spectra of Cu(EDTA) 1:1 were recorded, both 'as prepared' (pH 5.0), and after the addition of ammonium carbonate in different amounts until pH 6.0 and 8.0 were reached (see Supplementary Materials Figure S3). The spectra confirm that a Cu(EDTA) complex forms in acidic medium, in agreement with the literature [35]. Furthermore, the intensity at λ max = 239 nm gradually increases with pH; this matched well with the increase in EDTA complex stability with pH.…”

Bio-dielectric based on superconductors yttrium calcium barium copper oxide (YCaBa2Cu3O7−x ) from eggshell as calcium oxide source via sol-gel process

“…The other peak of the YCaBCO samples fired at 900 • C and 1,000 • C was at 3,450-3,500 cm −1 for ν (O-H) due to the water molecule in their structures. Furthermore, Thuy et al [21] described the FTIR results of YBCO showing a sharp peak at 565 cm −1 for Y 2 O 3 and BaCO 3 , assigned to ν (Y-O) and ν (Ba-O), respectively, while Ozabaci [22] suggested peaks of YBCO assigned at 588 cm −1 , 1,026 cm −1 , 1,085 cm −1 , and 1,216 cm −1 for ν (Y-O-Y). The strong absorption bands of YBCO located at 591 cm −1 and 701 cm −1 were assigned to the vibration of Cu-O.…”