Quantification of Fe 2+ /Fe 3+ by Electron Microprobe Analysis – New Developments
Quantification of Fe 2+ /Fe 3+ by Electron Microprobe Analysis – New Developments
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通过电子显微探针分析定量 Fe 2+ /Fe 3+ – 新进展
DOI：
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发表时间：
2003
期刊：
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通讯作者：
H. Höfer
中科院分区：
文献类型：
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作者：
H. Höfer
如果采用新的自吸收校正方法，利用电子探针（侧翼法）测量FeLα和FeLβ的软x射线发射光谱可以测定矿物中的铁氧化态。结果表明，用侧翼法得到的FeLβ/FeLα比值与穆斯堡尔四极分裂和晶体学数据相关。这可以用阳离子取代的铁配位多面体的连续畸变来解释。因此，电子探针数据意外地揭示了晶体学部位静电场的细节。虽然与其他方法相比，超精细参数的分辨率较低，但电子探针测定Fe2+/Fe3+具有以下几个优点：(i)所需的样本量小，（ii）采样体积小于1 μ m3， （iii）同时进行原位Fe3+/Fe3+测定和定量化学分析，（iv）简单的常规样品制备，(v)与同步加速器相比，电子探针的可用性很好。
The measurement of the soft FeLα and FeLβ X-ray emission spectra by electron microprobe (flank method) allows the determination of the iron oxidation state in minerals if our new method for self-absorption correction is applied. It can be shown that the FeLβ/FeLα ratios obtained with the flank method correlate with Mossbauer quadrupole splitting and crystallographic data. This can be explained by the successive distortion of the iron coordination polyhedra with cation substitution. Thus, the electron microprobe data unexpectedly reveal details of the electrostatic field at the crystallographic site. Although the resolution with respect to hyperfine parameters is lower compared to other methods, the Fe2+/Fe3+ determination by electron microprobe bears several advantages: (i) the small sample amount needed, (ii) the small sampling volume ⩽ 1 µm3, (iii) the simultaneous in situ Fe3+/Fe3+ determination and quantitative chemical analysis, (iv) the easy routine sample preparation, (v) the ready availability of an electron microprobe in comparison to a synchrotron.