Studies of the Superconductor YBCO

Activate the prepared sols by the addition of 1 M NaOH to give a pH of 10.5. Then add 1 M cadmium perchlorate solution dropwise until the intensity of fluorescence reaches a maximum, when the excess [Cd ] is -6x10 M. Record the fluorescence spectra when different pH values are used. 

The observed disappearance of electrical resistance when mercury and a few other alloys were cooled at liquid He temperature, led to die term superconductors. Only in 1986 did an oxide exhibit superconductivity and at higher transition temperatures, T. The following year the ceramic oxide YB2Cu307. (or YBCO) was found to become superconductor at a temperature 77 K (the boiling point of nitrogen). The ease of its preparation and its study makes it an interesting material. 

Provided the temperature of heating Y2O3, BaC03 and CuO is kept at - 930 C for a long time, the resulting compound exhibits superconductivity at -I96 C. 

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