Dielectric properties of $CsLiB_6O_{10}$(CLBO) single crystal were investigated for the frist time in the frequency range of 100 Hz to 1 MHz and in the temperature range of 100℃ to 600℃. Debye type relaxation behavior was observed below 400℃ in the frequency range of 10~100KHz, which is due to the hopping of non-bonding Cs ions to the nearby vacancy sites. However, as the temperature increases above 400℃, dc ionic conduction becomes more prominent. The barrier activation energy of Cs ions was estimated to be 4.38 eV from the Einstein-Nernst type conductivity theoretical fit.
The ionic conduction behavior is more clearly manifested in the a-direction than in the c-direction. This is explained by the structural characteristics of CLBO crystals in which Cs ions are located along the channels provided by the infinite helical chains of $LiB_3O_7$ networks along the a-direction, while in the c-direction Cs ions are intercepted by Li ions which sit right above and below the Cs ions.
For comparison the dielectric properties of $Li_2B_4O_7$ crystals were also studied in which Li ions play a dominant role of ionic conduction instead of Cs ions in case of CLBO.
It was found that the use of a thin insulation layer(0.3㎛) between the dielectric sample and metal electrodes was essential for reliable dielectric and conductivity measurements since, without the insulation layers, the ionic charges become neutralized as they get to the metal electrodes and they will no longer be able to contribute either to the dielectric relaxation or to the electrical conduction.
