Structural Specific Features Of Solid Solutions Ndxgd1-Xcr3(Bo3)(4)

Optical investigations of crystals of solid solutions NdxGd1 - Cr-x(3)(BO3)(4), 0.01 <= x <= 1, have been performed. Absorption spectra in the range of wavenumbers 11 000-15 000 cm(-1) recorded at cryogenic temperatures (16 K) reveal a significant effect of the concentration of Nd3+ ions in the structure on the absorption in the near infrared range of the spectrum due to f-f transitions in the Nd3+ ion. It has been found that, at a concentration of > 0.6, two nonequivalent Nd3+ centers are observed in the absorption spectra, which is explained by the presence of two polytypic modifications.