Influence of Factors on Growth of Off-Congruent LiNbO3Single-Crystal by Li-Rich/Li-Poor Chemical Vapor TransportEquilibration.

Influence of factors on growth ofoff-congruent LiNbO3single-crystal by Li-rich/Li-poorchemical vapor transport equilibration(VTE) was studied. These factors include the molar ratio of raw materialsLi2CO3and Nb2O5for preparingtwo-phase crucible, the hollow space volume for VTE growth, and theperiod of use of two-phase crucible. To achieve the goal, a numberof off-congruent LiNbO3plates were grown by Li-rich/Li-poorVTE technique using four two-phase crucibles having different molarratios of raw materials, hollow space volumes, and periods of use.The VTE-induced crystal composition alteration was characterized bymeasurement of birefringence. A comparison of results of differentcrucibles shows that in the Li-rich VTE case the first factor hasless effect, while the latter two may cause a difference of Li2O content as much as 0.4 mol %. Larger hollow space volumeand older crucible tend to degrade the VTE growth efficiency. Instead,the growth by Li-poor VTE is less affected by the three factors becauseof much lower Li2O gas pressure and hence slow growth ratein comparison with that by Li-rich VTE. [ABSTRACT FROM AUTHOR]