[19p-H112-1~15] 15.1 Bulk crystal growth

[19p-H112-8] Oxygen Partitioning during Growth of Congruent Lithium Niobate (3)

〇Satoshi Uda¹, Chihiro Koyama¹ (1.IMR, Tohoku Univ.)

Keywords:oxide,oxygen,activity

During oxide crystal growth metal to oxygen ratio does not hold in the solute diffusion boundary layer. This means that the amount of oxygen is excess or deficient relative to those of metals. We observed the variation of crystallization EMF for the growth of MgO-doped LN crystal from the melt. Combining the variation mode of EMF with thermodynamic analysis, we conclude that the activity of oxygen in the diffusion boundary layer is equal to that of oxygen in the solid that can be unity and hence the oxygen amount in the melt is equal to that in the solid, which is basically constant regardless of growth conditions. Then we conclude that the deviation from the stoichiometry of metals to oxygen is attributed to the change of metal quantity from the initial bulk melt composition.