Abstract
The phase diagram of nonhydrated has been determined by changing the Na content using a series of chemical reactions. As increases from 0.3, the ground state goes from a paramagnetic metal to a charge-ordered insulator (at ), then to a “Curie-Weiss metal” (around 0.70), and finally to a weak-moment magnetically ordered state (). The unusual properties of the state at (including particle-hole symmetry at low and enhanced thermal conductivity) are described. The strong coupling between the Na ions and the holes is emphasized.
- Received 16 December 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.247001
©2004 American Physical Society