Abstract
We study the influence of the lattice structure, the Jahn-Teller effect, and the Hund's rule coupling on a metal-insulator transition in . The difference in the lattice structure favors (fcc) being a metal and (bct) being an insulator, and the coupling to Jahn-Teller phonons favors being nonmagnetic. The coupling to ( ) phonons decreases (increases) the value of the Coulomb integral at which the metal-insulator transition occurs. There is an important partial cancellation between the Jahn-Teller effect and the Hund's rule coupling.
- Received 20 October 1999
DOI:https://doi.org/10.1103/PhysRevLett.84.1276
©2000 American Physical Society