Anisotropy of oxygen transport in YBa₂Cu₃O₇: The role of the [1/2, b,0] tunnels

We calculated the potential of interstitial oxygen in YBa2Cu3O7 using effective medium theory. We found that there is no potential energy barrier for oxygen motion in the [1/2, b,0] tunnel. Oxygen motion in the a and c directions requires overcoming barriers of 1.7 and 1.6 eV. Implications for superconductivity and oxygen diffusion are given. © 1988 Elsevier Science Publishers B.V.