Growth of heavily doped LiNbO3:Ce crystals, their physicochemical and optical characteristics and defect structure

Abstract

A series of LiNbO3:Ce crystals was grown using the Czochralski method in a wide range of dopant concentrations ([Ce] = 0.55–2.41 wt% in the melt). The physicochemical characteristics of the crystal-melt Li2O-Nb2O5-CeO2 system during the growth of the LiNbO3:Ce crystals have been studied. Optical characteristics and defect structure of the crystals were studied using the methods of photoinduced light scattering (PILS), laser conoscopy, optical spectroscopy and XRD. In the range of dopant concentrations in the crystal [Ce] ≈ 0.8–0.88 wt%, pronounced threshold effects have been detected in the LiNbO3:Ce crystals. It has been shown that LiNbO3:Ce crystals with a high dopant concentration can be used as “black” lithium niobate – a temperature-independent acoustoelectronic material free from pyroelectric effects.