Abstract
We study the combined influence of spin double exchange and Jahn-Teller lattice coupling to holes in the perovskites ( ). Using a mean-field approximation for the double exchange and a variational Lang-Firsov approximation for the lattice degrees of freedom, we show that the lattice effects decrease the magnetic transition temperature, and also cause the maximal value of the transition temperature as a function of dopant concentration to depend on the Jahn-Teller coupling strength. We find a continuous rapid crossover from a large polaronic state to a quasi-self-trapped small polaron state accompanying the magnetic transition.
- Received 5 July 1995
DOI:https://doi.org/10.1103/PhysRevLett.76.1356
©1996 American Physical Society