PART IVSUPERCONDUCTIVITYSuperconductivity SummaryThe complexities in understanding superconducting perovskities can be greatly simplified by using the Circular Model of the Atom. The nonstoichiometric chemical compounds can be understood in terms of distinctive and separate positive-negative fields. Negative spin elements (like oxygen in the Circular Model) need more units to reach charge neutrality. (Ex. the planes of copper II oxide, needing more oxygen to achieve superconductivity). Substitution of negative configuration spin elements (like nickel) have the effect of killing superconductivity in a very graphic way when using the Circular Model. Opposite is the effect of overloading the anion with an abundance of positive element cations. Rare earth ions generally substitute for Y or La in high Tc compounds because the valence electrons that are given up are in the S shell area of the periodic table (Circular Model). The electrons that are added in each succeeding element are buried within the 4F shell and have little impact upon superconductivity. Even the rare earth elements with large magnetic moments (Gd and Eu) are superconducting because the ionization of rare earth elements to the 3+++ state occurs in the highly positive area of each rare earth element. |