Investigation of Optical and Structural Homogeneity of Ca4GdO(BO3)3 Single Crystals

Abstract

Optical and structural homogeneity of undoped Ca4GdO(BO3)3 crystals grown from the melt by the Czochralski method in the [010] direction was investigated by spectroscopic measurements and using an automated spectropolarimeter over the entire area of the samples in the wavelength range between 660 and 800 nm. A fair to good optical quality of the investigated crystals was found. Those results are compared with chemical etching experiments.

Color Centers in Ca4GdO(BO3)3Single Crystals Irradiated by Gamma Quanta

“…The fundamental absorption edge of crystal is above 47000 cm −1 , in the region below the crystal is transparent. The absorption spectrum of the GdCOB sample exhibits a small absorption coecient value in the wave number region between 31250 cm −1 and 9000 cm −1 and broad absorption bands of color centers are not present.There is a convincing evidence for a good optical quality of this crystal.In the UV region the three groups of intensive absorption peaks near 40160 cm −1 , 36360 cm −1 and 32260 cm −ground state to the 6 D J , 6 I J , and J excited levels, respectively[6,7].After irradiation by gamma quanta with dose 2 × 10 Gy the growth of absorption in crystal transparence region is observed and wide AA in the region arise in GdCOB crystal spectrum(Fig. 2).…”

Dielectric constant tensor of piezoelectric gadolinium calcium oxoborate crystal, GdCa4O(BO3)3, estimated from the electric impedance spectrum

“…There are many publications devoted to the optical properties of GdCOB (e.g. [3][4][5][6][7][8]) as well as some devoted to its elastic and piezoelectric properties [9][10][11][12]. The dielectric properties of the crystal are reported only by Wang et al [9].…”