Pressure-induced squeezing-out of electrons in cuprate superconductors

✍ Scribed by Kosuke Odagiri

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 833 KB
• Volume: 244
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00060-7

✦ Synopsis

The pressure dependence of Tc in cuprate superconductors is found to contradict well-known correlations between T m~x and Madelung potential differences. The reason for this anomaly is explored by considering the inter-ionic core-core repulsion which gives a large correction to the electronic potential when ions are brought close together. The repulsive correction calculated for the case of CU(sheet)-"O(sheet) bond can also be applied to compounds at ambient pressure. This leads to the convergence in the scatter of data points on the T ~ vs. A V M graph by 30%. In particular, the application to the case of the T~ variation in RE-124 is found to give a good agreement with experiment. Other known correlations involving T m~x are discussed. In particular, the correlation between T~ and the inter-layer distance d is attributed to the corresponding variations in za VM.