DIFFERENCE OF VARIATION OF UNIT CELL VOLUME V AND Tc WITH OXYGEN CONTENT IN YBa2Cu3O7−x AND LaBa2Cu3O7+x

In YBa2Cu3O7−x, the more the oxygen content is the higher is the Tc, the smaller is the lattice parameter c and the unit cell volume V. But in LaBa2Cu3O7+x the less the oxygen content is, the higher is the Tc, the larger are c and V. These may be due to oxygen content being less than 7.0 in YBa2Cu3O7−x and more than 7.0 in LaBa2Cu3O7+x. These results give some informations regarding superconducting mechanism and show that the one-dimensional chain plays an important role.