Level crossing between NQR and tunnel systems in (NH4)2SnCl6
- 30 May 1982
- journal article
- Published by IOP Publishing in Journal of Physics C: Solid State Physics
- Vol. 15 (15) , 3381-3390
- https://doi.org/10.1088/0022-3719/15/15/010
Abstract
The authors have observed a peculiar behaviour in the NQR relaxation of both chlorine isotopes in (NH4)2SnCl6below 80K. An unusual ratio T1(37Cl)/T1(35Cl) approximately=2.4 at low temperatures can be explained by the dipolar coupling to the tunnelling ammonium protons causing relaxation by a mechanism similar to that for the proton NMR relaxation, but at slower rates. A very large maximum value around 55K is ascribed to relaxation of the tunnel system towards the lattice, after resonant transfer of energy from the NQR system. It is argued that this relaxation time should be of the same order of magnitude as the proton T1at similar frequencies and temperatures.Keywords
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