The frequency and temperature dependences of the dielectric constant, dielectric loss and alternating-current conductivity were studied by using single crystals and a combination of quenching, laser excitation, alternating current field treatment and X-irradiation. The measurements were performed at frequencies ranging from 100Hz to 10MHz, and temperatures ranging from 30 to 400C. The dielectric constant at 30C was equal to 8.4, and was independent of the frequency, while the dielectric loss was less than 0.001 at 100Hz. The results indicated that the various treatments appreciably increased the room-temperature and high-temperature dielectric constant and dielectric loss values in the low-frequency region. Arrhenius plots of the conductivity at 100Hz indicated that the activation energy for conduction in the intrinsic region was equal to 0.97eV for as-cleaved LiF. This value decreased in variously treated samples. These treatments helped to increase the concentration of charged lattice defects and, in turn, increased the dielectric constant and dielectric loss.

P.Selvarajan, B.N.Das, H.B.Gon, K.V.Rao: Journal of Materials Science, 1994, 29[15], 4061-4