Crozier Peter A, Leibovich Matan, Haluai Piyush, Tan Mai, Thomas Andrew M, Vincent Joshua, Mohan Sreyas, Marcos Morales Adria, Kulkarni Shreyas A, Matteson David S, Wang Yifan, Fernandez-Granda Carlos
Materials Science and Engineering, School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, USA.
Courant Institute of Mathematical Sciences, New York University, New York, NY, USA.
Science. 2025 Feb 28;387(6737):949-954. doi: 10.1126/science.ads2688. Epub 2025 Feb 27.
Materials functionalities may be associated with atomic-level structural dynamics occurring on the millisecond timescale. However, the capability of electron microscopy to image structures with high spatial resolution and millisecond temporal resolution is often limited by poor signal-to-noise ratios. With an unsupervised deep denoising framework, we observed metal nanoparticle surfaces (platinum nanoparticles on cerium oxide) in a gas environment with time resolutions down to 10 milliseconds at a moderate electron dose. On this timescale, many nanoparticle surfaces continuously transition between ordered and disordered configurations. Stress fields can penetrate below the surface, leading to defect formation and destabilization, thus making the nanoparticle fluxional. Combining this unsupervised denoiser with in situ electron microscopy greatly improves spatiotemporal characterization, opening a new window for the exploration of atomic-level structural dynamics in materials.
材料的功能可能与发生在毫秒时间尺度上的原子级结构动力学相关。然而，电子显微镜以高空间分辨率和毫秒时间分辨率对结构进行成像的能力常常受到低信噪比的限制。通过一个无监督深度去噪框架，我们在中等电子剂量下，在气体环境中以低至10毫秒的时间分辨率观察了金属纳米颗粒表面（氧化铈上的铂纳米颗粒）。在此时间尺度上，许多纳米颗粒表面在有序和无序构型之间持续转变。应力场可以穿透到表面以下，导致缺陷形成和不稳定，从而使纳米颗粒具有流动性。将这种无监督去噪器与原位电子显微镜相结合，极大地改善了时空表征，为探索材料中的原子级结构动力学打开了一扇新窗口。
