Dielectric properties of quenched and laser-excited or field-treated LiF single crystals irradiated with X-rays

✍ Scribed by P. Selvarajan; B. N. Das; H. B. Gon; K. V. Rao

• Publisher: Springer
• Year: 1994
• Tongue: English
• Weight: 327 KB
• Volume: 29
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00355970

✦ Synopsis

Frequency and temperature dependences of dielectric constant, K, and loss, tan 8, and hence a.c. conductivity, o, have been studied for LiF single crystals under a combination of treatments such as quenching, laser excitation, a.c. field treatment and X-ray irradiation. The measurements were made in the frequency range 102-107 Hz and in the temperature range 30-400~

The dielectric constant, K, of LiF at 30~ was found to be 8.4 and to be independent of frequency, while the dielectric loss, tan8, was below 10 -3 at 102 Hz. The results indicate that the different treatments on LiF single crystals increase the room-temperature and also high-temperature K and tan 8 values appreciably in the lowfrequency region. Log ~ versus 1/T plots at frequency 1 02 Hz give the activation energy for conduction in the intrinsic region as 0.97 eV for as-cleaved LiF; this value was found to decrease in variously treated LiF samples. The different treatments on LiF help to increase the concentration of charged lattice defects which, in turn, increases the K and tan 8 values.