The determination of low boron concentrations in silicate glasses by electron probe microanalysis (EPMA) remains a significant challenge. The internal interferences from the diffraction crystal, i.e. the Mo-B4C large d-spacing layered synthetic microstructure crystal, can be thoroughly diminished by using an optimized differential mode of pulse height analysis (PHA). Although potential high-order spectral interferences from Ca, Fe, and Mn on the BKα peak can be significantly reduced by using an optimized differential mode of PHA, a quantitative calibration of the interferences is required to obtain accurate boron concentrations in silicate glasses that contain these elements. Furthermore, the first-order spectral interference from ClL-lines is so strong that they hinder reliable EPMA of boron concentrations in Cl-bearing silicate glasses. Our tests also indicate that, due to the strongly curved background shape on the high-energy side of BKα, an exponential regression is better than linear regression for estimating the on-peak background intensity based on measured off-peak background intensities. We propose that an optimal analytical setting for low boron concentrations in silicate glasses (≥0.2 wt% B2O3) would best involve a proper boron-rich glass standard, a low accelerating voltage, a high beam current, a large beam size, and a differential mode of PHA.

中文翻译：

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改进硅酸盐玻璃中硼浓度的电子探针显微分析。

通过电子探针微分析（EPMA）测定硅酸盐玻璃中的低硼浓度仍然是一项重大挑战。通过使用优化的脉冲高度分析微分模式（PHA），可以彻底消除衍射晶体（即Mo-B4C大d间隔层状合成微结构晶体）的内部干扰。尽管可以通过使用优化的PHA差模来显着降低Ca，Fe和Mn对BKα峰的潜在高阶光谱干扰，但仍需要对干扰进行定量校准，才能获得包含这些元素的硅酸盐玻璃中准确的硼浓度元素。此外，来自ClL线的一阶光谱干扰非常强，以至于阻碍了含Cl硅酸盐玻璃中硼浓度的可靠EPMA。我们的测试还表明，由于BKα高能侧的强烈弯曲背景形状，在基于测得的非高峰背景强度估算高峰背景强度时，指数回归优于线性回归。我们建议对于硅酸盐玻璃中低硼浓度（≥0.2wt％B2O3）的最佳分析设置最好包括适当的富硼玻璃标准液，低加速电压，高束流，大束流大小和差值。 PHA模式。