NMR study of antiferromagnetic black sodalite Na 8(AlSiO 4) 6
Abstract
27Al and 29Si NMR spectra and spin-lattice relaxation in heavily sodium-doped sodalite Na 8(AlSiO 4) 6 are presented. The magnetic hyperfine shifts of 27Al and 29Si have Curie-Weiss-type temperature dependences with the same Weiss parameter Θ=-168±5 K. From an abrupt broadening of the resonance lines the transition temperature to the antiferromagnetic phase TN=54±2 K is determined. Above 200 K thermally activated ionic motion (activation energy, EA/ kB=2000 K) is found in sodalite cages containing Na 43+ ions which is much slower than the motion ( EA/ kB=750 K) in the cages containing Na 33+ ions.
- Publication:
-
Chemical Physics Letters
- Pub Date:
- September 2000
- DOI:
- 10.1016/S0009-2614(00)00859-9
- Bibcode:
- 2000CPL...327..131H