TY - JOUR
T1 - Impedance measurement and equivalent circuit analysis of binary alkali silicate melts
AU - Harada, Yusuke
AU - Saito, Noritaka
AU - Nakashima, Kunihiko
N1 - Publisher Copyright:
© 2019 ISIJ.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/3
Y1 - 2019/3
N2 - Molten oxides such as silicate melts are used in glass manufacturing processes and the chemical structure of the melts affects their physical properties and hence, the efficiency of the process in which they are used and the quality of the manufactured product. Analysis of the chemical structures using Raman or nuclear magnetic resonance spectroscopy is time consuming due to the process of preparing quenched samples and the long relaxation time of atomic nuclei. Hence, a technique for faster structural analysis is desirable. In this study, in order to accumulate basic data for in-situ estimation of the network structures of molten oxides, we systematically investigated the relationships between the alkali oxide composition and measured impedance behavior. Nyquist plots were fitted using an equivalent circuit consisting of solution resistance, charge transfer resistance, and double layer capacitance. In the present samples, the solution resistance and charge transfer resistance decreased, and double layer capacitance increased with increasing K + concentration. These results were attributed to K + behaving as a charge carrier or the double layer becoming thinner due to increasing concentration of K + ions, which increased interfacial polarization. We observed that the solution and charge transfer resistances increased, and double layer capacitance decreased, in the order of Li, Na, and K. Hence, these resistances were dependent on the ionic radius, as well as the macrostructure of the melts.
AB - Molten oxides such as silicate melts are used in glass manufacturing processes and the chemical structure of the melts affects their physical properties and hence, the efficiency of the process in which they are used and the quality of the manufactured product. Analysis of the chemical structures using Raman or nuclear magnetic resonance spectroscopy is time consuming due to the process of preparing quenched samples and the long relaxation time of atomic nuclei. Hence, a technique for faster structural analysis is desirable. In this study, in order to accumulate basic data for in-situ estimation of the network structures of molten oxides, we systematically investigated the relationships between the alkali oxide composition and measured impedance behavior. Nyquist plots were fitted using an equivalent circuit consisting of solution resistance, charge transfer resistance, and double layer capacitance. In the present samples, the solution resistance and charge transfer resistance decreased, and double layer capacitance increased with increasing K + concentration. These results were attributed to K + behaving as a charge carrier or the double layer becoming thinner due to increasing concentration of K + ions, which increased interfacial polarization. We observed that the solution and charge transfer resistances increased, and double layer capacitance decreased, in the order of Li, Na, and K. Hence, these resistances were dependent on the ionic radius, as well as the macrostructure of the melts.
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U2 - 10.2355/isijinternational.ISIJINT-2018-602
DO - 10.2355/isijinternational.ISIJINT-2018-602
M3 - Article
AN - SCOPUS:85063933596
VL - 59
SP - 421
EP - 426
JO - Transactions of the Iron and Steel Institute of Japan
JF - Transactions of the Iron and Steel Institute of Japan
SN - 0915-1559
IS - 3
ER -