Analysis of the thickness dependence of critical current density for electrophoretically deposited YBa2Cu3O7−x films

Abstract

An attempt has been made to explain the experimental observations regarding variation of critical current density with the film thickness between 3 and 65 μm in electrophoretically deposited YBa2Cu3O7−x films on silver (Ag) substrates. It is not possible to explain the phenomenon using the commonly believed concept of self-field degradation of critical current density of weak links between the grains. On the other hand, an increased grain-boundary resistance due to a lesser degree of silver penetration from the substrate with increasing film thickness is proposed to be the cause of the observed degradation of critical current density. The experimental data agree quite well with those theoretically calculated.

Preparation and characterization of YBa2Cu3O7−xthick films deposited on silver substrates by the electrophoretic deposition technique for magnetic screening applications

“…We used a classical formulation of the EPD process from data in the literature [2][3][4][5][6][7][8][9], and used a set of process parameters which were optimized for our experimental conditions.…”

“…The first attempt was reported by Koura et al [2,3], who stated that EPD was a suitable way to obtain HTS thick films on silver substrates with a critical temperature higher than the boiling point of liquid nitrogen. Following that, many other investigations were carried out in order to find the set of process parameters giving the best coatings [4][5][6][7][8][9]. Now, EPD is a well known technique to form ceramic materials of different shapes [10].…”

J c enhancement of electrophoretically deposited YBa2Cu3O7−δ superconducting wire by BaF2 addition

“…As a strategy to reduce the cracks, the YBCO deposition was usually repeated two or three times along with heat treatment near 920°C between depositions. 5,6,8 With this multiple deposition process, Casãn-Pastor et al 8 and Zhang et al 6 increased J c to 209 A/cm 2 and 500 A/cm 2 at 77 K, respectively. However for practical applications involving superconducting wire and tape, a stable and reproducible technique is required to reduce the cracks developed in the YBCO layer.…”

“…Electrophoretic ͑electrophysical͒ deposition [1][2][3][4][5][6][7][8][9][10][11][12][13] is an effective technique to deposit YBa 2 Cu 3 O 7Ϫ␦ ͑YBCO͒ on an irregularly shaped substrate with a simple setup. Many groups have studied this method with various metal substrates ͑Ag, 1-8 Au, 7 Pt, 7 Cu, 9,10 Ni,7,8 Ni-Cr, 7 Kanthal, 7 stainless steel 12 12 and ZrO 2 /stainless steel 12 ͒.…”