Optical Properties of CaNb2O6 Single Crystals Grown by OFZ*

CaNb2O6 single crystals with an orthorhombic columbite structure are grown via an optical floating zone (OFZ) method. The as-grown crystals are colorless and free of low-angle grain boundaries and inclusions. They are transparent (up to 62%) in the visible to the infrared region (400-1000 nm) and have a low absorption coefficient (alpha = 1.56). The bandgap is determined as a direct transition and E-g = 4.28 eV. The wavelength-dependent refractive index and extinction coefficient of the CaNb2O6 crystals are derived from the obtained T and alpha spectra. Their photoluminescence spectra exhibit a strong and broad emission band centered at 465 nm.

Automated summary

CaNb2O6 single crystals with an orthorhombic columbite structure are grown via an optical floating zone method. These crystals are transparent, low in absorption coefficient, and have a bandgap of 4.28 eV. They exhibit a strong photoluminescence at 465 nm.