“Crystallization E.M.F.” Investigation in the lithium niobate pulling process from the melt

Abstract

. in the lithium niobate crystal-melt system as a function of pulling and rotation rates, crystal diameter and orientation was determined. Total E.M.F. is a sum of thermo-E.M.F. and "crystallizationwhere u is a growth rate, dq, = 3.9 mV, u,, = 1.9 mm/h is adequate. The A q magnitude is independent within the experimental error on the rotation rate and crystal orientation, whereas it is slightly increasing along with the diameter increase. Some existing models of electric phenomena accompanying crystal growth are discussed and a new model based on charge carrier injection into solid during growth is proposed.

Study of the mechanism of crystallization electromotive force during growth of congruent LiNbO3 using a micro-pulling-down method

“…The Df-DT curve was similar to the ones reported in Ref. [6] and [12]. In our Df-DT curve, a deflection was observed in the solid phase at around DT ¼ 170 K. This was attributed to the sudden change in the growth rate.…”

“…In their reports, even though D'yakov et al [6] and Aleksandrovskii and Shumov [12] reported similar measurements using a Czochralski method, the mechanism of crystallization EMF was not elucidated. D'yakov et al [6] considered the crystallization EMF, Df EMF , to be linearly proportional to the growth rate and represented it in the form Df EMF ¼ a V V, where a V and V represent a linear constant and the growth rate, respectively.…”

“…However, the linear dependence was valid only for very low growth rates and we found in this work that Df EMF showed nonlinear dependence for higher growth rates. Later, Aleksandrovskii and Shumov [12] carefully studied on the phenomena and demonstrated a nonlinear dependence of Df EMF on the growth rate. However, their explanation for the mechanism of Df EMF , lacked consideration of the ionic conductivity of the system.…”

Electric current induced compositional variation in LiNbO3 fiber crystal grown by a micro-pulling down method

“…D'yakov et al [1] and Aleksandrovoskii et al [2] demonstrated the intrinsic electric potential distribution occurring around the solid-liquid interface, which consists of thermoelectric power (Seebeck effect) and electromotive force (EMF) during the growth of congruent LiNbO 3 by the Czochralski method. Uda and Tiller [3] discussed that EMF is associated with a charge separation effect resulting from the net charge by all existing ions in the melt which has a simple relationship with the growth velocity.…”

Influence of impurity doping on the partitioning of intrinsic ionic species during the growth of LiNbO3 crystal from the melt

“…Therefore, we must differentiate the partitioning of ionic species from that of bulk components. Segregation of ionic species at the congruent composition was experimentally observed during growth of LN crystal using the Czochralski method by measuring the crystallization EMF generated near the growth interface [10,11].…”