  Single crystals of KNbO3 and KNbO3 : Fe have been grown using the flux method
at various technological conditions. The investigations of optical absorption
of these crystals were carried out. Marked influence of technological
conditions and doping with iron on optical absorption has been found. Observed
changes of the absorption spectra are associated with lattice defects arising
due to nonstoichiometry and/or doping.

Condensed Matter