2008/07/10 by Stanford R. Ovshinsky, Ovshinsky, S. R.
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.0807.1673
openalex publication_date 2008/07/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the cuprate and iron-pnictide systems, valence changes induce high-temperature superconductivity while the local structural chemistry and local spin order both independently generate the attractive interactions responsible for the high transition temperature. We argue that together they favor d-wave singlet superconductivity in the cuprates but s-wave singlet in the pnictides. This difference arises from the existence of a large on-site repulsion between carriers in the cuprates largely absent in the pnictides. Fluorine is responsible for raising Tc significantly in some pnictides and in the cuprates to 155K-168K, the highest achieved at ambient pressure. We propose an experimental procedure for finding and fabricating the fluorinated cuprate phase having that exceptional property.