TY - JOUR
T1 - Effect of interface electric field on partitioning during the growth of conventional and true congruent-melting LiNbO3 crystals
AU - Shi, Qilin
AU - Nozawa, Jun
AU - Uda, Satoshi
N1 - Funding Information:
This work was supported in part by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, by a Grant-in-Aid for Scientific Research on Exploratory Research (No. 16H03855). The authors also would like to express thanks to Mr. I. Narita, IMR, Tohoku University, for assistance with the EPMA measurements.
Funding Information:
This work was supported in part by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, by a Grant-in-Aid for Scientific Research on Exploratory Research (No. 16H03855 ). The authors also would like to express thanks to Mr. I. Narita, IMR, Tohoku University , for assistance with the EPMA measurements.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - 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.
AB - 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.
KW - A1. Growth models
KW - A1. Impurities
KW - A1. Segregation
KW - A2. Crystallization electromotive force
KW - A2. Growth from melt
KW - B1. Oxides
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U2 - 10.1016/j.jcrysgro.2020.125864
DO - 10.1016/j.jcrysgro.2020.125864
M3 - Article
AN - SCOPUS:85090590159
SN - 0022-0248
VL - 549
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
M1 - 125864
ER -