Melt fraction, distribution and interconnection determined by electrical conductivity (EC) and energy dispersive X-ray diffraction (EDX) measurements
Melt fraction, distribution and interconnection determined by electrical conductivity (EC) and energy dispersive X-ray diffraction (EDX) measurements
复制标题
通过电导率 (EC) 和能量色散 X 射线衍射 (EDX) 测量确定熔体分数、分布和互连
DOI：
10.1127/zdgg/2017/0101
复制
发表时间：
2017
影响因子：
1.1
通讯作者：
von der Gönna
中科院分区：
文献类型：
--
作者：
von der Gönna
本文研究了在0.3GPa压力和400-1500 ℃温度范围内拉布拉多玄武岩和玄武岩中熔体体积分数的原位检测。使用的方法是频率依赖电导率（EC）和能量色散X射线衍射（EDX）。这些技术允许在原位压力和温度条件下测定熔体分数，而对淬火样品进行光学分析（SEM）。EC允许检测熔体分数低至0.03，由于介电性能的变化。增加熔体分数导致以前孤立的熔体气泡互连沿着晶界，从而增加了体积电导率。因此，电导率为熔体的形成（介电性质）和熔体的互连程度（体积电导率）两者提供了量度。能量色散X射线衍射实验（EDX）提供了一个额外的测量熔体的体积分数。EDX衍射数据用于基于峰背景比计算熔体的体积分数。在最后一步中，将实验数据（SEM、EC、EDX）与熔体分布的几何模型，即Archie-、立方体-、管-、Hashin-Shtrikman HS+和HS-模型进行比较。电的“极化率”数据密切配合HS+模型，而体积电导率数据被发现是不太敏感的熔体分数检测。
This study deals with the in-situ detection of volume fractions of melt in labradorite and basalt at 0.3 GPa pressure and temperatures ranging from 400-1500 C. Methods used were frequency dependent electrical conductivity (EC) and energy dispersive X-ray diffraction (EDX). These techniques allowed melt fraction determination under in-situ pressure and temperature conditions, while optical analysis (SEM) was performed on quenched samples. EC allowed detecting melt fractions as low as 0.03 due to changes in dielectric properties. Increasing melt fractions caused the formerly isolated melt bubbles to interconnect along grain boundaries, thus increasing the bulk conductivity. Electrical conductivity thus provides a measure for both, the formation of melt (dielectric property) and the degree of interconnection of melt (bulk conductivity). Energy dispersive X-ray diffraction experiments (EDX) provided an additional measure for the volume fraction of melt. EDX diffraction data were used to calculate the volume fraction of melt on the basis of the peak to background ratio. In a final step the experimental data (SEM, EC, EDX) were compared with geometric models of melt distribution, namely the Archie-, cube-, tube-, Hashin-Shtrikman HS+and HS-model. The electrical" polarisability" data closely fit the HS+model, while bulk conductivity data were found to be less sensitive for melt fraction detection.