Shimizu Masahiro, Sato Kenzo, Nakashima Kento, Kiyosawa Tomohiro, Matsuoka Jun, Shimotsuma Yasuhiko, Miura Kiyotaka
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
School of Engineering, The University of Shiga Prefecture, Hikone 522-8533, Japan.
J Chem Phys. 2022 Jun 7;156(21):214504. doi: 10.1063/5.0090939.
Using a laser-induced local-heating experiment combined with temperature analysis, we observed the composition-dependent sign inversion of the Soret coefficient of SiO in binary silicate melts, which was successfully explained by a modified Kempers model used for describing the Soret effect in oxide melts. In particular, the diffusion of SiO to the cold side under a temperature gradient, which is an anomaly in silicate melts, was observed in the SiO-poor compositions. The theoretical model indicates that the thermodynamic mixing properties of oxides, partial molar enthalpy of mixing, and partial molar volume are the dominant factors for determining the migration direction of the SiO component under a temperature gradient.
通过结合温度分析的激光诱导局部加热实验，我们观察到二元硅酸盐熔体中SiO的索雷特系数随成分变化的符号反转，这一现象通过用于描述氧化物熔体中索雷特效应的改进肯佩斯模型得到了成功解释。特别是，在贫SiO成分中观察到了SiO在温度梯度下向冷侧的扩散，这在硅酸盐熔体中是一种反常现象。理论模型表明，氧化物的热力学混合性质、混合偏摩尔焓和偏摩尔体积是决定温度梯度下SiO组分迁移方向的主要因素。
