Ferromagnetism and Superstructure in Ca1-xLaxB6
Abstract
We critically investigate the model of a doped excitonic insulator, which has recently been invoked to explain some experimental properties of the ferromagnetic state in Ca1-xLaxB6. We demonstrate that the ground state of this model is intrinsically unstable towards the appearance of a superstructure. In addition, the model would lead to a phase separation of doped carriers into electron-enriched and neutral domains, which may be prevented by Coulomb forces only. Recent experiments indicate that a superstructure may indeed show up in this material.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2000
- DOI:
- 10.1103/PhysRevLett.84.2207
- arXiv:
- arXiv:cond-mat/9906401
- Bibcode:
- 2000PhRvL..84.2207B
- Keywords:
-
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 4 pages, 2 figures, submitted to PRL