Relationship between cohesive energy and superconductivity in Hg-system superconductors

Calculation of cohesive energy on Hg-system superconductors HgBa2CuOy(1201), HgBa2CaCu2Oy(1212), HgBa2 Ca2Cu3Oy(1223), HgBa2Ca3Cu4Oy(1234), and HgBa2Ca4Cu5Oy(1245) has been made. A program was developed to claculate the combinative energy between Cu-O planes and remaining parts, and between blocks in the superconductors. The result indicates that if the cell is considered as the two blocks combined together, a close relationship among the combinative energy of the two blocks, the value of T-c, and the number of the Cu-O planes in the Hg-system superconductors is established. The result gives a new way to understand the change of the value of T-c as the number of the Cu-O planes. In contrast, the combinative energy between the Cu-O planes and the remains got from the method separating all the Cu-O planes from the cell and leaving some discrete remaining parts does not show any relationship with the value of T-c. This means that considering the cell as the two blocks in more reasonable, and the interaction between the two blocks plays an important role in superconductivity.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)5ARTICLE10745-7471