Interactions in YBa2Cu3O7−x aqueous suspensions

YBa2Cu3O7−x dispersion in iodine acetone for electrophoretic deposition: Surface charging mechanism in a halogenated organic media

“…It has been demonstrated elsewhere [18] that surface dissolution occurs when YBCO particles are suspended in water. Carbonation and Hydroxilation of solved ions affects to the concentration of potential determining ions (H + and OH + ), fixing the suspension stability.…”

“…An acidification tendency of the suspension media can be noted when solid concentration increases. Although suspensions are prepared in acetone both, the environmental humidity and the water content of technical grade acetone, promotes the slow carbonation of the Ba 2+ leached from the YBCO particle surfaces [18]. The surrounding conditions of YBCO particles are a consequence of the powder dissolution and related reactions.…”

“…Consequently, YBCO surface reactions affect to the surface charge even in organic media [18]. Indeed, both suspension parameters solids and water content determine YBCO particle stability in acetone, being key for later shaping process.…”

“…The presence of ions produced by the YBCO dissolution in 10 g/l suspensions fits the increase of conductivity. If the amount of water is larger the charging mechanism by selective adsorption of ions (H + , Ba 2+ and Ba(OH) + ) on hydrated surfaces [18] should displace the donor-acceptor mechanism. In those cases, stability conditions should be studied and adjusted, because of those YBCO suspensions lead to heterogeneous deposits (figure 3d).…”

“…Degradation of YBCO in water has been observed, mainly due to an incongruent dissolution of Ba 2+ . Later carbonation and/or hydroxylation of Ba 2+ [13,14] determine the surface charge behaviour of YBCO in aqueous suspensions [15][16][17][18].…”