Abstract
The 19F- self-diffusion has been investigated in PbF2, up to the melting point, by NMR techniques. Relaxation time measurements (T1, T2 and T1 rho ) have been made from 300 to 1095K. Anomalous behaviour above 500K, similar to that reported in previous investigations, is found to be due to paramagnetic impurity produced as a result of the high reactivity of PbF2 at these temperatures. Direct F- diffusion measurements have been made using NMR spin echoes from 570K to 1005K. These results are compared with those of ionic conductivity and are found to be 0.88+or-0.10 eV, assuming a vacancy mechanism of self-diffusion is operative. Above the phase transition at 705K the F- diffusion coefficient changes more slowly with temperature, being characterised by an activation energy of 0.20+or-0.02 eV, which is typical of a fast ion conductor.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
