Interaction of YBCO and PbO2 particles in acetone

The interaction of YBCO and PbO2 particles suspended in acetone were determined using particle size and zeta potential measurements. Results show that YBCO particles are positively charged when mixed in acetone, while PbO2 particles were determined to be negatively charged. In addition, upon testing the suspension of YBCO+PbO2 in acetone, zeta potential measurements show a decrease in magnitude with respect to settling time. The addition of more PbO2 into the YBCO-acetone suspension also pushed its zeta potential values to the unstable region (|ζ| < 30 mV). This explains why the sedimentation deposition fails to produce high quality films because of the relatively strong Coulombic attraction of YBCO and PbO2 particles when mixed in acetone. The agglomeration of particles during the sedimentation deposition results to a non-uniform substrate surface coverage.