In:
The Journal of Chemical Physics, AIP Publishing, Vol. 80, No. 3 ( 1984-02-01), p. 1272-1278
Abstract:
Both cw and pulsed NMR measurements on the two naturally abundant isotopes of thallium 203Tl and 205Tl and on fluorine 19F have been made in TlNb2O5F as a function of temperature and frequency. The temperature dependence of the Tl resonance linewidth gives an Arrhenius activation energy of 0.08 eV. The wide line spectra indicate the presence of nucleus–electron–nucleus indirect interaction. T1 and T2 measurements of both isotopes demonstrate thermally activated motion of Tl+. The nonexponentiality of spin lattice relaxation leads us to introduce two relaxation times corresponding to two motions of Tl ions giving two activation energies—0.25 and 0.14 eV. A consistent interpretation of these results can be given in terms of an exchange interaction between the two isotopes of Tl associated with a jump from cavity to cavity, and a chemical shift interaction associated with a swing from site to site inside a same cavity of the rigid network NbO5F.
Type of Medium:
Online Resource
ISSN:
0021-9606
,
1089-7690
Language:
English
Publisher:
AIP Publishing
Publication Date:
1984
detail.hit.zdb_id:
3113-6
detail.hit.zdb_id:
1473050-9
