[论文解读] Irradiation-induced amplification of electric fields at oxide interfaces as revealed by correlative DPC-STEM and DFT

Elizabeth A. Peterson, Dongye Liu+6 more|arXiv (Cornell University)|Mar 12, 2026

Fusion materials and technologies被引用 0

一句话总结

这篇论文将DFT缺陷-电子结构建模与相关的4D-STEM DPC 和 EELS 结合起来， показывает irradiation 放大 Fe2O3–Cr2O3 金属氧化物异质结构界面的电场，电场方向和大小取决于界面原子结构。

ABSTRACT

Heterointerfaces are ubiquitous in modern devices, found in technologies ranging from microelectronics to structural components for energy applications. Many of these emerging technologies are found in applications such as satellites, batteries, and next generation nuclear reactors, that are subject to harsh environments. In some scenarios, multiple extreme conditions, such as irradiation and corrosion, act on the material simultaneously. Extending the lifetime of these technologies is dependent on a detailed understanding of how their component materials platforms and interfaces respond in extreme environments, where irradiation and corrosion may couple in unique ways, distinct from corrosion under ambient conditions. Oxides, which form readily over metal underlayers, can act as protective coatings; enhancing the robustness of oxide overlayers to protect underlying metal alloys is a potential avenue towards corrosion mitigation. Here we study the impact of irradiation-induced non-equilibrium defects on charge segregation and electric fields at and near multi-phase oxide heterointerfaces. We perform a detailed study of irradiated Fe2O3-Cr2O3 thin film heterostructures using first-principles DFT electronic structure modeling paired with 4D-STEM DPC and EELS techniques to measure nanoscale changes in electric fields. Our results show clear evidence that irradiation drives substantial modulation of interfacial electric fields that can be tailored by controlling the atomistic chemical structure of the oxide interface. We show that irradiation can selectively induce built-in electric fields, thereby altering their direction; this suggests a pathway to engineering protective oxide heterostructure overlayers that can electrically control the spatial distribution of defects, with significant implications for the design of corrosion-resistant materials for extreme environments.

研究动机与目标

• Understand how irradiation-induced defects affect charge segregation and built-in fields at Fe2O3–Cr2O3 oxide interfaces.
• Investigate how interfacial atomistic structure (abrupt vs mixed) modulates electrostatics and defect migration under irradiation.
• Correlate DFT defect energetics with nanoscale electric-field measurements to assess corrosion implications in extreme environments.
• Explore potential routes to design oxide heterostructure overlayers that control defect distributions via interfacial electrostatics.

提出的方法

• Compute interfacial electronic structure with DFT+U for abrupt and mixed Fe2O3–Cr2O3 interfaces to obtain layer-resolved DOS and band offsets.
• Perform 4D-STEM DPC with PED-DPC to map out-of-plane electric fields across oxide interfaces at nanometer scale.
• Use EELS-based thickness mapping to normalize CoM shifts and quantify local E-field via Gauss’s law (rho = ε0 dEz/dz).
• Extract integrated interfacial potentials by integrating the FFT-smoothed E-field profiles over ~50 nm around the interface.
• Model oxygen vacancies (VO0, VO+1, VO+2) in DFT to assess defect-induced band-edge shifts and their impact on interfacial offsets.
• Compare experimental field maps with DFT-predicted band offsets and defect-induced shifts to interpret irradiation effects.

Figure 1: The atomistic chemical and structural details of each interface type and associated layer-resolved density of states. For the (a) abrupt interface, each cation layer only contains one type of cation, Fe (gold) or Cr (blue), while for the (d) mixed interface the interfacial cation layer con

实验结果

研究问题

• RQ1 How does irradiation modify interfacial electric fields at Fe2O3–Cr2O3 interfaces?
• RQ2 How does atomistic interfacial structure (abrupt vs mixed) influence defect segregation and electrostatics under irradiation?
• RQ3 Can irradiation-induced defect populations modify band offsets and drive directional charge transfer across oxide heterointerfaces?
• RQ4 Do bulk versus interfacial defect populations differentially affect the interfacial electric field strength and corrosion propensity?

主要发现

• Irradiation drives substantial modulation of interfacial electric fields, with built-in fields that can reverse or amplify depending on interface type.
• Abrupt interfaces show stronger field amplification under irradiation (maxima ~+2.5 MV/cm, minima ~−3.0 MV/cm) and integrated potential change of +0.71 V across ~50 nm, nearly doubling the pristine magnitude and reversing sign.
• Mixed interfaces exhibit notable but smaller field amplification under irradiation, with integrated potential up to +0.24 V.
• DFT with oxygen vacancies shows defect-induced band-edge shifts that favor electron transfer to the irradiated oxide, with larger offsets for abrupt interfaces.
• Experimentally, irradiated samples exhibit broadened field distributions and net charge density imbalances that tend to localize near the interface, yet average neutrality is approached within ±50 nm.
• DFT indicates that defects in the bulk have a larger impact on the electric field than defects clustered exactly at the interface, suggesting sustained interfacial fields if bulk defects persist

Figure 2: The setup and selected data for the 4D-STEM and DPC-PED measurements. HAADF image of (a) Cr 2 O 3 / Fe 2 O 3 mixed interface and (b) Fe 2 O 3 / Cr 2 O 3 abrupt interface after irradiation. (c) Schematic of the DPC-PED setup for oxide interfaces with a nearly parallel beam illumination. k x