Impact of growth atmosphere on langatate (La3Ga5.5Ta0·5O14) crystals grown by czochralski technique and its coloration

Langatate (LGT) crystals of La3Ga5.5Ta0·5O14 composition of diameter 50 mm were grown from the melt by Czochralski technique. Using (1–2 wt %) Ga2O3 excess in the starting charge and growing crystal in mixture argon (0.1–1%O2) gas atmosphere are a good condition to crystallize LGT under stationary stable regime. The LGT crystals grown along Z-axis exhibit strong faceting. The grown crystals were exempt of inclusions, cracks and secondary phases. The presence of oxygen in the growth chamber is necessary to limit gallium oxide evaporation and strongly affect the crystals coloration and the transmission spectra in the range (200–500 nm). The electrical resistivity is sensitive to the oxygen content in the growth environment.