Relationship between superconducting transition temperature and combinative energy in YBa2Cu3O7-delta

Separating the unit cell of YBa2 Cu-3 O7-delta into perovskite and rock salt blocks and considering the interaction between the two blocks, a computer program has been developed to calculate the interaction called combinative energy, between the blocks. The combinative energy in YBa2 Cu-3 O7-delta with different delta value from 0.07 to 0.62 has been calculated. A close relationship between the superconducting transition temperature and the combinative energy in YBa2 Cu-3 O7-delta has been established, and the change of the combinative energy found to be closely related to the transformation from orthorhombic I to II. It is believed that the interaction between the two blocks in the unit cell is of great importance to the superconductivity in YBa2 Cu-3 O7-delta.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)2ARTICLE6446-4481