Improved Glass Formation And Unique Structure Of Bi-Based Superconducting Precursor Glases With Some Additives

Bi-based superconducting precursor glasses with the compostions MxBi2Sr2Ca2Cu3Oy are prepared to improve the glass forming ability and to get information on glass structure. The main idea for these M3+ ion additions comes from the presence of delafossite type compounds having the formula CuMO2 in which two oxygen coordinated Cu+ has the role of combining octahedral MO6 units. Additions of Al203, Cr203 and Fe203 enhance the glass formation and particularly their addition of just around x=0.8 is the most effective.