Improvements of uniformity and stoichiometry for zone-leveling Czochralski growth of MgO-doped LiNbO3 crystals

Zone-leveling Czochralski growth and characterization of undoped and MgO-doped near-stoichiometric lithium tantalate crystals

“…The heating and cooling rates during annealing were held at 35 1C/h to release thermal stress. This is to emphasize that with the present zone composition (60 mol% Li 2 O), there were no obvious crystal ridges, presumably of Li 3 TaO 4 , on the surface of the grown crystals, which is contrary to the observation made in the case of LiNbO 3 , grown earlier by the authors [13][14][15]. The as-grown crystals were oriented by X-ray and then sliced into several wafers perpendicular to the c-axis along the growth axis by a precision ID saw (Model APD1, Logitech Co.).…”

“…A radiation shield was also used in SLT crystal growth to keep the solution zone stationary. The design of the radiation shield was similar to the design used by Tsai et al [14] for the growth of SLN crystals.…”

“…Recently we have developed a novel zone-leveling Cz (ZLCz) technique to grow stoichiometric lithium niobate (SLN) single crystals [13][14][15]. This technique is a combination of the zone melting and Cz techniques.…”

Problems and recent advances in melt crystal growth technology

“…[46] a Pt pipe, 2 mm in diameter and 20 mm in length at the bottom of inner crucible was used for communication, whereas authors of Ref. [47] preferred the holes with size less than 1 mm, and authors of Ref. [48] dwelled on large size windows with width equal to$one half of radius of inner crucible and height from 5 to 35 mm.…”

“…The crystals of improved quality (stoichiometric LiNbO 3 ) free of inclusions and bubbles were obtained by feeding the inner crucible with melt [47,49] that ensures much better maintaining of constant melt composition at the solid-liquid interface. Compared to the powder supplying double crucible technique, the advantage of the melt delivery technique is greater precision in the material supplying process, more rapid diffusion velocity of the melts, and facile operation.…”