Evidence for an Antiferromagnetic Transition in a Zeolite-Supported Cubic Lattice of F Centers
Abstract
Evidence for a bcc lattice of F centers in sodium-electro-sodalite (SES), synthesized by exposing dehydrated sodalite to sodium vapor, is presented. A high electron spin density in SES produces isotropic contact shifts in nuclear magnetic resonance (NMR) spectra of the framework nuclei whose magnitude is a discrete function of local electron density. Strong exchange coupling between unpaired electrons gives rise to an antiferromagnetic phase transition in SES at TN = 48+/-2 K, providing the first example of an s-electron antiferromagnet.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 1998
- DOI:
- 10.1103/PhysRevLett.80.2449
- Bibcode:
- 1998PhRvL..80.2449S