Improved film morphology after cold-bath quenching of electrophoretically deposited Bi₂Sr₂CaCu₂O₈ with LiCl as a supporting electrolyte

Abstract

This paper presents the effect of cold-bath quenching on the film morphology of Bi₂Sr₂CaCu₂O₈ fabricated using electrophoretic deposition with lithium chloride as a supporting electrolyte. Our setup deposited two sets of Bi-2212 films using finely ground Bi-2212 in ethanol with 8.09 wt% LiCl solution. The films were partially melted at 970°C, quenched, and annealed. One set was air quenched, and the other set was cold bath quenched. Scanning electron microscopy, x-ray diffraction, and resistance versus temperature measurements verified the properties of the films. The results show that all films are c-axis oriented and have transition temperatures of 88 K. The films quenched in a cold bath have smoother film morphology. A higher cooling rate after partial melting reduces grain boundaries without sacrificing the Bi-2212 film properties.