解析鉻和鐵在界面電化學反應中的交互作用：利用 HAXPES 和 ICP-MS 進行互補性分析

Abstract

理解複雜多元素材料中分子等級的電化學反應機制對於許多應用來說至關重要。在合金鈍化反應中，合金表面形成惰性的三氧化二鉻被認為是提高合金抗腐蝕性的機制。然而，在當前的討論，三氧化二鉻與其他元素的電化學交互作用還未被明確定義，尤其是三氧化二鉻和鐵之間的交互作用。因此，三氧化二鉻的應用受到一定的限制。在研究中，我們使用互補性分析，應用即時感應耦合電漿質譜儀監測以及非即時 X 射線光電子能譜儀來探討關於鉻和鐵的鈍化反應。為了提高表面分析的精確度，我們使用角度解析方法及結合雙陰極 X 光源，包括高能量硬 X 光光電子能譜儀。此方法可達到 12 奈米的非破壞性深度分析，並且分析化學態變化。在晶體場多重態理論下，我們的結果推測形成鉻-鐵混合氧化物結構，在近中性環境中能提供較好的抗腐蝕能力。

Understanding the electrochemical reaction mechanisms at the molecular level in complex multi-principal element materials is crucial for various applications. In alloy passivation reactions, the formation of an inert Cr2O3 surface is a widely accepted mechanism for enhancing alloy corrosion resistance. However, the electrochemical interaction between Cr2O3 and many other elements, particularly Fe, has not been well-defined in the current discussion. As a result, the applicability of the Cr2O3 passive film model is somewhat constrained. In this work, we utilize a complementary analysis strategy by applying in-situ inductively coupled plasma mass spectrometry (ICP-MS) monitoring, and ex-situ X-ray photoelectron spectroscopy (XPS) characterization to investigate the reaction of passive film involving Cr and Fe. To enhance the precision of surface analysis, we employ an angle-resolved approach in conjunction with dual-anode X-ray sources, including HAXPES. This method enables the non-destructive construction of a 12 nm depth profile, revealing variations in chemical states. Considering the crystal field multiplet theory, our results suggest the formation of a Cr-Fe mixed oxide structure that offers a broad potential range of passivity under near-neutral condition.