Abstract
The calcium fluoride (CaF2) single crystals were grown using the Bridgman technique. By optimizing growth conditions, <111>-oriented CaF2, crystals up to 20 mm in diameter were grown. Number of dislocations in CaF2 crystals was 5 × 104-2 × 105 per cm2. Selected CaF2 single crystals is cut into several tile diamond saw. The plates were polished, first with the silicon carbide, then with the paraffin oil and finally with a diamond paste. The obtained crystals were studied by X-ray diffraction, Raman spectroscopy, far-IR reflectivity and by the measurement of transmission in the mid-IR range. The crystal structure is confirmed by XRD. One Raman and two IR optical modes predicted by group theory are observed. In the transmission spectra, except modes originated from vibration of -CH2 groups, hydroxyl groups -OH and KBr, is visible a peak at 671 cm−1 assigned to the Ca-F stretching vibrations. A low photoluminescence testifies that the concentration of oxygen defects within the host of CaF2 is small. The electrical and dielectric properties of CaF2 single crystal were studied.
