Spark discharge generators (SDGs) employ controlled gaseous environments to induce spark ablation of non-insulating electrodes, resulting in the formation of various nanostructures in the gas phase. The method offers technological advantages such as continuous particle production, scalable yield, and minimal waste. Additionally, the versatility of the process enables the generation of alloy nanoparticles from various material combinations, including immiscible ones. In order to fully exploit its potential, understanding the atomic mixing process during electrode ablation, particularly in the case of dissimilar electrodes, is crucial. Temporally and spatially resolved optical emission spectroscopy (OES) has been previously demonstrated as an effective characterization tool for spark plasmas in SDGs. However, to gain a deeper insight into the vapor mixing process, it is essential to quantitatively determine the plasma composition in both space and time. This paper introduces a calibration-free OES-based method tailored for spark plasmas utilized in binary nanoparticle generation. The method introduces the so-called multi-element combinatory Boltzmann plots, which use intensity ratios of emission atomic lines from different materials, allowing for the direct estimation of total number concentration ratios. The approach is tested using synthetic spectra and validated with experimental spark spectra obtained near an alloyed gold-silver (AuAg) electrode with a known composition. The study demonstrates the capabilities and robustness of the proposed method, with a focus on the AuAg system due to its significance in plasmonic research and frequent synthesis using spark ablation.

中文翻译：

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一种确定用于金银二元纳米颗粒合成的火花放电等离子体成分的免校准发射光谱方法。

火花放电发生器（SDG）采用受控气体环境来诱导非绝缘电极的火花烧蚀，从而在气相中形成各种纳米结构。该方法具有连续颗粒生产、可扩展产量和最少浪费等技术优势。此外，该工艺的多功能性使得能够从各种材料组合（包括不混溶材料组合）中生成合金纳米颗粒。为了充分发挥其潜力，了解电极烧蚀过程中的原子混合过程，特别是在不同电极的情况下，至关重要。时间和空间分辨发射光谱 (OES) 先前已被证明是 SDG 中火花等离子体的有效表征工具。然而，为了更深入地了解蒸气混合过程，必须定量确定空间和时间上的等离子体成分。本文介绍了一种基于直读光谱仪的免校准方法，专为二元纳米颗粒生成中使用的火花等离子体而定制。该方法引入了所谓的多元素组合玻尔兹曼图，该图使用不同材料的发射原子线的强度比，可以直接估计总数浓度比。该方法使用合成光谱进行测试，并使用在已知成分的合金金银 (AuAg) 电极附近获得的实验火花光谱进行验证。该研究展示了所提出方法的功能和稳健性，重点关注金银系统，因为它在等离子体研究和使用火花烧蚀的频繁合成中具有重要意义。