Operando Imaging of Strain and Defects at the Nanoscale

Nanomaterials are profoundly influenced by defects, which can either enhance or impede their properties, contingent on the intended application. In semiconducting nanomaterials, defects can alter conductivity and optical properties by introducing states within the band gap. Similarly, in catalyst nanoparticles, defects can augment chemical reactivity and selectivity through active sites. The mechanical properties of metals can be either strengthened or weakened depending on the controlled introduction of defects. In magnetic nanomaterials, defects are pivotal in determining coercivity, magnetic susceptibility, and saturation magnetization, while in optical materials, they can significantly affect luminescence and absorption properties. In the context of battery cathode nanomaterials, defects can either facilitate or obstruct ion movement, thus impacting performance. Given this complexity, the identification and spatial resolution of defects and structural dynamics in nanomaterials are crucial for both fundamental understanding and practical applications. This presentation will delve into our group's pioneering work in employing x-ray Bragg Coherent Diffractive Imaging (BCDI). BCDI is a cutting-edge technique that enables imaging of 3D strain and defects with atomic scale volumetric resolution. We have applied BCDI to investigate semiconductor, magnetic, metallic, and battery nanostructures, offering unprecedented insights into their structural dynamics in-operando.