TY - JOUR
T1 - Effect of atmosphere on the surface tension and viscosity of molten LiNbO3 measured using the surface laser-light scattering method
AU - Nagasaka, Yuji
AU - Kobayashi, Yusuke
N1 - Funding Information:
This paper is the result of the cooperative research project “Metrological study of thermophysical properties of liquids and high temperature melts” between Japan Space Utilization Center and Keio University, and has been financially supported in part by New Energy Industrial Development Organization. Professor Taketoshi Hibiya of Tokyo Metropolitan University is gratefully acknowledged for his valuable suggestions. The authors would also like to thank Masato Ohnishi, who helped in the initial phases of designing the apparatus and to Shinichiro Hara for his assistance with the experiment.
PY - 2007/9/1
Y1 - 2007/9/1
N2 - The surface tension and the viscosity of molten LiNbO3 (LN) having the congruent composition have been measured simultaneously in a temperature range from 1537 to 1756 K under argon gas and dry-air atmospheres. The present measurement technique involves surface laser-light scattering (SLLS) that detects nanometer-order-amplitude surface waves usually regarded as ripplons excited by thermal fluctuations. This technique's non-invasive nature allows it to avoid the experimental difficulties of conventional techniques resulting from the insertion of an actuator in the melt. The results of surface tension measurement obtained under a dry-air atmosphere are about 5% smaller than those obtained under an argon atmosphere near the melting temperature, and the temperature dependence of the surface tension under a dry-air atmosphere is twice that under an argon atmosphere. The uncertainty of surface tension measurement is estimated to be ±2.6% under argon and ±1.9% under dry air. The temperature dependence of viscosity can be well correlated with the results of Arrhenius-type equations without any anomalous behavior near the melting point. The viscosities obtained under a dry-air atmosphere were slightly smaller than those obtained under an argon atmosphere. The uncertainty of viscosity measurement is estimated to be ±11.1% for argon and ±14.3% for dry air. Moreover, we observed the real-time dynamic behavior of the surface tension and the viscosity of molten LN in response to argon and dry-air atmospheres.
AB - The surface tension and the viscosity of molten LiNbO3 (LN) having the congruent composition have been measured simultaneously in a temperature range from 1537 to 1756 K under argon gas and dry-air atmospheres. The present measurement technique involves surface laser-light scattering (SLLS) that detects nanometer-order-amplitude surface waves usually regarded as ripplons excited by thermal fluctuations. This technique's non-invasive nature allows it to avoid the experimental difficulties of conventional techniques resulting from the insertion of an actuator in the melt. The results of surface tension measurement obtained under a dry-air atmosphere are about 5% smaller than those obtained under an argon atmosphere near the melting temperature, and the temperature dependence of the surface tension under a dry-air atmosphere is twice that under an argon atmosphere. The uncertainty of surface tension measurement is estimated to be ±2.6% under argon and ±1.9% under dry air. The temperature dependence of viscosity can be well correlated with the results of Arrhenius-type equations without any anomalous behavior near the melting point. The viscosities obtained under a dry-air atmosphere were slightly smaller than those obtained under an argon atmosphere. The uncertainty of viscosity measurement is estimated to be ±11.1% for argon and ±14.3% for dry air. Moreover, we observed the real-time dynamic behavior of the surface tension and the viscosity of molten LN in response to argon and dry-air atmospheres.
KW - A1. Ripplon surface laser-light scattering method
KW - A1. Surface tension
KW - A1. Thermophysical properties
KW - A1. Viscosity
KW - A2. Growth from melt
KW - B1. Lithium niobate
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U2 - 10.1016/j.jcrysgro.2007.01.050
DO - 10.1016/j.jcrysgro.2007.01.050
M3 - Article
AN - SCOPUS:34548127811
VL - 307
SP - 51
EP - 58
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
IS - 1
ER -