Electronic mechanism of critical temperature variation in RBa2Cu3O7−δ

• Main Authors: Chen, Xiao Jia, Su, Haibin
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Magnetic materials
• Online Access: https://hdl.handle.net/10356/93915; http://hdl.handle.net/10220/6929
• Institution: Nanyang Technological University

We have performed systematic studies of the trend of the critical temperature Tc due to both Madelung site potential difference between in-plane oxygen and copper sites ΔVM and interlayer effect in the optimally doped 123 superconductors RBa2Cu3O7−δ. ΔVM is found to decrease with the increase of the trivalent rare-earth ionic radius rR3+. This change enhances the next-nearest-neighbor hopping integral t', which results in the experimentally observed increase of Tc with rR3+. The coherent interlayer single-particle hopping t⊥ has a more profound effect than t' on the nearly linear trend of Tc as a function of rR3+. These results reveal the importance of the electronic origin of the rare-earth ionic size effect on Tc in this family.