The effect of quenching upon the disorder of fluoride ions, and the resultant ionic conductivity of single crystals, was studied by means of impedance measurements. It was observed that samples which were quenched from a higher temperature had a higher conductivity (8 x 10-6S/cm) and a lower activation energy (0.70eV) in the extrinsic region between 260 and 460C.

B.G.Ravi, N.Baskaran, S.Ramasamy: Materials Chemistry and Physics, 1997, 47[1], 57-61