Abstract
The substitution effects of Ni and Zn for Cu in Bi(Pb)-Sr-Ca-Cu-O system have been studied. The transition temperature Tc decreases at nearly the same rate with the Ni and Zn contents in 2212 phase. The impurities also depress the transition temperature in 2223 phase. It is suggested that the depression of Tc is not caused by reduction of hole concentration, change of unpaired d electron numbers, oxygen vacancies, or, related to it, the formal average valence state of Cu , but is rather due to the partial elimination of the singlet bound state formed from the combination Cu 3d x2 - y2 - O 2 p σ We also discussed the structure disorder which may bring about impurity scattering and localization effects.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
