Ethylenediamine solutions have been shown to turn bulk YBCO into insulating materials. The effect of these solutions on thin YBCO films is studied. In both unpatterned and patterned films, a smooth decrease in critical currents, a transition to normal state, and a subsequent gradual increase in resistance are observed as a function of exposure time to the solution. It is noted that these characteristics might make this process desirable for weak-link and on-film resistor fabrication.
James, P. M.; O'Callaghan, J. M.; Application of selective leaching in fabrication of thin film YBCO devices. IEEE Transactions on applied superconductivity, 1993, vol. 3, núm. 1, p. 2972-2974.