Daniel A. Nepela

Correlation of electronegativity and transition temperature in high-Tc superconductors

Abstract If pairing in high-temperature superconductors is mediated by charge fluctuations, then critical temperature should scale with the difference in electronegativities between anions and cations (Δ χ ). We demonstrate that, in fact, T c scales linearly with Δ χ .

Magnetic, surface, and corrosion properties of Ni‐Fe‐Pd thin films

Films in the Ni‐Fe‐Pd ternary system were evaporated and characterized with regard to magnetic properties, resistance to atmospheric corrosion, and surface composition. It was found that Pd behaves like Ni magnetically and results in little magnetic dilution. High moments can be maintained at high Pd concentrations. Low coercive forces exist in a trough from Ni0.8Fe0.2 to Fe0.7Pd0.3 in the ternary composition field. The magnetoresistance was found to be significantly less than for Ni0.8Fe0.2 (Permalloy) in all other composition regions. Pd addition at low concentrations caused the alloy atmospheric corrosion to increase and then decrease for higher Pd addition. The surface of these alloys is enriched in Fe and O while the oxide‐alloy interface shows significant Pd enrichment. The oxide thickness increases with the addition of Fe.