Optimization of the electrophoretic deposition of YBa2Cu3O7?x superconducting large area coatings

Abstract

Abstract. Large area coatings (>10cm 2) of the high temperature superconductor YBa2Cu307-x (x = 0.1 -0.2) (YBCO) have been prepared by scale up an electrophoretic deposition technique using silver sheets and Si-wafers coated with Ag or Au as substrates. Several parameters, like the kind of the solvent, the applied voltage, the distance between the electrodes, the initial concentration of the suspension and the temperature during the electrophoresis were investigated in order to attain high deposition rates, as well as uniform YBCO coatings with the proper stoichiometry. To obtain a strongly adherent and dense coating a subsequent appropriate sintering and annealing procedure has been developed. The coatings obtained were characterized for their stoichiometry and superconducting properties by X-ray diffraction (XRD), Raman spectroscopy and magnetic measurements. The homogeneity and thickness of the films and the average grain size of the deposited particles have been investigated by optical and scanning electron microscopy (SEM).Key words: YBa2Cu3OT-high temperature superconductor, large area coatings, electrophoretic deposition, Raman spectroscopy, magnetic susceptibility.Applications of To-superconducting coatings for passive microwave devices and shielding of magnetic fields require the development of reproducible processes for the deposition of high temperature superconductors (HTS) on large area substrates [1][2]. In * To whom correspondence should be addressed recent years electrophoretic deposition of high To superconductors has been studied intensively [3][4][5][6][7][8][9][10][11]. This technique has the advantage of producing economically uniform and dense coatings with controllable thickness on various substrates with different shapes and sizes and can easily be adapted to large area and continuous fabrication [12].The optimization and scale up an of earlier developed electrophoretic deposition technique [13][14] is investigated in this paper and is applied to large area substrates of several cm 2. Different parameters affecting the electrophoretic velocity have been investigated in detail in order to increase the deposition rate, the uniformity and density of the coatings, keeping the correct stoichiometry of YBa2Cu3OT-x(X=0.1-0.2) (YBCO). The electrophoretic deposition technique used in the fabrication of YBCO coatings requires conductive substrates in order to be useful as electrodes, not reactive with YBCO, having a smooth surface for the good adherence of the superconducting powder, similar thermal expansion as the coating in order to avoid cracks in the thermal treatment and higher melting point than YBCO for the followed sintering process [151.The substrates tested in this work were Ag-sheets and plates and Si-wafers coated with thin films of Ag or Au (700-800 ~t), produced by the vapor deposition technique.To improve the homogeneity, adhesion and density of the electrophoretically deposited coatings an appropriate sintering and annealing procedure has

Analytical Techniques Applied in Optimization of Electrophoretic Deposition of Thin Film YBCO Superconductors

“…The thickness of the coatings was 5 mm, depending on the deposition time [13], as observed by optical microscopy. The thickness of the coatings was 5 mm, depending on the deposition time [13], as observed by optical microscopy.…”

“…The YBCO powder was suspended in acetone in an electrophoretic cell as described elsewhere [12,13]. The YBCO powder was suspended in acetone in an electrophoretic cell as described elsewhere [12,13].…”

Production and characterization of MgB2 coatings on various substrates by electrophoretic deposition

“…In the present study, a simplified electrophoretic deposition technique, originally developed for the production of YBCO 123 and BSCCO 2212 high temperature superconducting coatings [8][9][10], was modified and applied for the fabrication of MgB 2 coatings by direct deposition of MgB 2 superconducting powder on the substrate. The suitability of several substrates, such as commercial metallic plates (Ag, Ni, stainless steel) or Si/Pt wafers was also investigated.…”

Transformation of MgB2 powder into superconducting film via electrophoretic deposition technique

“…Thick films have great potential applications in magnetic shielding and high power antenna [6]. In recent years different techniques, such as screening printing [2,7], sol-gel [8], solution spray [9], partial melting technique [10], electrocrystallization [11][12][13], and electrophoretic deposition (EPD) have been used for the fabrication of thick films of MgB 2 [14][15][16][17][18][19] and high-T c superconductors [20,21]. The electrophoretic deposition is a very simple and rapid technique, which enables single or double-sided coatings on desired substrates with any shape.…”