Abstract Doping of 4.7 mol% MgO into LiNbO3 (LN) with 50 mol% Nb2O5 enables it to be simultaneously stoichiometric and congruent (denoted as cs-MgO:LN). The equilibrium partitioning coefficient, k0, is unity; therefore, it is expected that no segregation of any ionic species occurs during crystal growth, and thus cs-MgO:LN is regarded as a true congruent-melting material. However, the segregation of ionic species was experimentally observed during the growth of a cs-MgO:LN crystal grown by the micro-pulling down (μ-PD) technique because of the formation of an intrinsic interface electric field related to the Seebeck effect caused by a high temperature gradient near the solid–liquid interface, thus changing k0 to non-unity. An external current was injected into the solid–liquid interface to compensate the intrinsic electric field and it was experimentally shown that the true congruent-melting state of cs-MgO:LN was achieved, which was confirmed by a homogenous Mg distribution near the interface that led to a k0 of unity for all constituent species, including ionic species. The relationship between the melt and the growing LN crystal is revealed to be a metal-n type semiconductor junction.

中文翻译：

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界面电场对常规和真全同熔 LiNbO3 晶体生长过程中分配的影响

摘要 将 4.7 mol% MgO 掺杂到具有 50 mol% Nb2O5 的 LiNbO3 (LN) 中使其能够同时具有化学计量和全等（表示为 cs-MgO:LN）。平衡分配系数 k0 为 1；因此，预计在晶体生长过程中不会发生任何离子物质的偏析，因此 cs-MgO:LN 被认为是真正的同质熔融材料。然而，在通过微下拉 (μ-PD) 技术生长的 cs-MgO:LN 晶体的生长过程中，通过实验观察到离子物质的分离，因为形成了与引起的塞贝克效应相关的本征界面电场。通过固-液界面附近的高温梯度，从而将 k0 变为非单位。将外部电流注入固-液界面以补偿本征电场，实验表明实现了 cs-MgO:LN 的真正全等熔化状态，这通过界面附近的均匀 Mg 分布证实导致所有成分物种（包括离子物种）的 k0 统一。熔体与生长中的 LN 晶体之间的关系被揭示为金属-n 型半导体结。