COMMENTS ON THE ISOTOPE EFFECT IN THE 90K OXIDE SUPERCONDUCTORS

In this letter, we point out that the Batlogg et al. experiment does not indicate that in the oxide superconductors Ba₂YCu₃O₇ and Ba₂EuCu₃O₇, the isotope effect, if existed. would be very small, but instead, shows that the coupling between electron and the high frequency lattice vibration involving oxygen is weak.