Abstract
An unconventional microscopic mechanism relating and the isotope substitution for the doped superconductors such as the high- oxides is proposed. Strong nonadiabaticity, when it is impossible, strictly speaking, to separate fully the nuclear and electronic degrees of freedom, leads to a peculiar dependence of the carrier concentration n on the ionic mass M. This case corresponds, for example, to the isotopic substitution of the axial oxygen in . Because of the dependence of on n, this leads to the dependence of on M, that is to the isotope effect. The minimum value of the isotope coefficient corresponds to =.
- Received 10 August 1993
DOI:https://doi.org/10.1103/PhysRevB.49.3652
©1994 American Physical Society