Dispersant-free colloidal fabrication of Bi2Sr2CaCu2O8 superconducting thick films

Abstract

Bi2Sr2CaCu2Ox thick films have been fabricated using colloidal processing. The composition of the suspension has been optimised using sedimentation experiments and rheological measurements. It has been stated that well-dispersed suspensions of Bi2Sr2CaCu2Ox can be obtained when ethanol is used as a solvent without the addition of deflocculants. Using the fits of the viscosity curves to the Krieger-Dougherty model, it has been possible to determine that the maximum volume fraction of solids leading to stable suspensions is 0.37. With these suspensions, it has been possible to fabricate films with 130 μm in thickness that show enough resistance to cracking and allow easy handling. Superconducting coatings have been obtained without dispersant.