Electronic mechanism of critical temperature variation in RBa2Cu3O7−δ
Chen, Xiao Jia
Date of Issue2005
School of Materials Science and Engineering
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.
Physical review B
© 2005 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The paper can be found at: [DOI: http://dx.doi.org/10.1103/PhysRevB.71.094512]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.