DIELECTRIC-PROPERTIES OF BETA-BARIUM BORATE AND POTASSIUM PENTABORATE SINGLE-CRYSTALS

Single crystals of beta barium borate and potassium pentaborate (commonly known as beta-BaB2O4 or BBO and KB5O8. 4 H2O or KB5) were grown by high and low temperature solution growth methods, respectively. The dielectric constant and loss tangent were determined as a function of temperature. Frequency response of the dielectric constant and tan delta have been studied over a frequency range of 0.1 - 100 kHz; it is found that both the dielectric constant and tan delta decrease with increase in frequency for both crystals. The dielectric constant and tan delta are found to increase with increase in temperature for both the crystals. Further, the dielectric constant and tan delta measured on different orientations of the grown crystals reveal the anisotropic nature of the crystals.