کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1790286 1524423 2014 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Partitioning of ionic species during growth of impurity-doped lithium niobate by electric current injection
ترجمه فارسی عنوان
تقسیم بندی گونه های یونی در طول رشد نیتروژن لیتیوم ناخالص با تزریق جریان الکتریکی
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
چکیده انگلیسی
MgO-doped lithium niobate that is simultaneously congruent and stoichiometric, denoted cs-MgO:LN (Li2O:Nb2O5:MgO=45.3:50.0:4.7) [1], has a partition coefficient of unity for each of its constituent species, including ionic species. As such, this material exhibits no segregation of ions during crystal growth. However, a crystallization electromotive force (c-EMF) is observed during growth by the micro-pulling down (μ-PD) method, due to segregation of the cs-MgO:LN ionic species. This arises from a steep temperature gradient at the solid-liquid interface that generates an electric field due to the Seebeck effect. In this case, the equilibrium partition coefficient, k0, must be modified to kE0 to take into account the effect of an electric field on the partitioning of ionic species. A coefficient of kE0 rather than k0 has a value of non-unity and therefore can lead to generation of a c-EMF. An electric current was injected into the melt in such a way that the Seebeck effect was canceled, and this demonstrated that the value of k0 is unity for all constituent ionic species of cs-MgO:LN. It has thus been confirmed that an injected electric current reduces the c-EMF. Only cs-MgO:LN attained a zero c-EMF value at a specific current that was valid at all growth rates, whereas s-MgO(2.5 mol%):LN and ZnO-doped LN required velocity-dependent currents to reduce their c-EMFs to zero. The observation of a zero c-EMF at all growth rates upon removing the Seebeck field effect indicates that the value of k0 is unity for all constituent species of cs-MgO:LN in both the melt and crystal phases, including ionic species. Therefore, the activity of all components of cs-MgO:LN in both phases is unity and this compound is simultaneously stoichiometric and congruent.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Crystal Growth - Volume 406, 15 November 2014, Pages 78-84
نویسندگان
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