Magnetic susceptibility measurements of Bi2Sr2Ca1-xYxCu2O8+δ
In the Bi 2212 system the crystallographic site occupied by Ca is similar to that occupied by Y in the YBCO system. For this reason it is believed that Y can substitute for Ca in Bi 2212. With this type of substitution Y is in the +3 ionization state whereas Ca is in the +2 state. Substitution of Y for Ca in Bi 2212, therefore, leads to neutralization of available holes lowering the carrier concentration and thus the Tc. Previously reported effects of Y substitution on Tc came from resistivity measurements. Magnetic susceptibility measurements are more sensitive to the presence of superconducting phases than resistivity measurements. We report here the magnetic susceptibility measurements of Y substituted Bi 2212 bulk superconductors.